Olefin polymerization catalyst and process for preparing polypropylene and propylene block copolymer

ABSTRACT

Olefin polymerization catalysts are formed from:  
     (I-1) a contact product obtained by contacting  
     (A) a solid titanium catalyst component,  
     (B) an organometallic compound catalyst component, and  
     (C) a specific organosilicon compound,  
     (D) a specific polyether compound and, optionally,  
     (II-1)  
     (III) an organometallic compound catalyst component; or  
     (I-2) a contact product obtained by contacting  
     (A) a solid titanium catalyst component,  
     (B) an organometallic compound catalyst component, and  
     (D) a specific polyether compounds,  
     (C) a specific organosilicon compound, and, optionally,  
     (II-2)  
     (III) an organometallic compound catalyst component; or  
     the contact product (I-1) or (I-2) may be replaced by one which is obtained by prepolymerizing an olefin of 2 or more carbon atoms in the presence of the catalyst components for the contact product (I-1) or (I-2).

CROSS REFERENCE TO RELATED APPLICATIONS

[0001] This is a division of application Ser. No. 08/730,930, filed Oct.16, 1996, now allowed; which is a division of application Ser. No.08/690,054, filed Jul. 31, 1996, which issued as U.S. Pat. No.5,618,886; which is a continuation of application Ser. No. No.08/289,635, filed Aug. 12, 1994.

FIELD OF THE INVENTION

[0002] The present invention relates to novel olefin polymerizationcatalysts and processes for preparing polypropylenes and propylene blockcopolymers using the novel catalysts. The present invention also relatesto processes for preparing propylene block copolymers using specificolefin polymerization catalysts.

[0003] The polypropylene according to the present invention has a highisotacticity. The propylene block copolymer according to the presentinvention contains a polypropylene component having a high isotacticityand a rubber component having a high intrinsic viscosity [η].

BACKGROUND OF THE INVENTION

[0004] There have been known homopolypropylene generally havingexcellent rigidity and heat resistance, and propylene block copolymerscomprising both polypropylene component and a rubber component andhaving excellent rigidity and heat resistance as well as excellentimpact resistance.

[0005] Propylene polymers have also a low specific gravity and can beeasily recycled, and therefore, they have been paid much attention withrespect to environmental protection and are now desired to be moreextensively utilized.

[0006] Such propylene polymers are prepared using so-called aZiegler-Natta catalyst comprising a compound containing a transitionmetal of Group IV to VI of the periodic table and an organometalliccompound containing a metal of Group I to III, and they are widely used.

[0007] However, the propylene polymers obtained by the prior arttechniques have not always sufficient rigidity and heat resistance insome uses, so that they have limited uses for some purposes.

[0008] It is known that the rigidity and the heat resistance ofpropylene polymers can be further improved by increasing theisotacticity of homopolypropylene or a polypropylene component in apropylene block copolymer, in other words, these properties can beimproved by the use of a catalyst capable of providing a highisotacticity for the propylene polymers in the preparation thereof.

[0009] However, a polymer of an olefin such as propylene obtained by theuse of such a catalyst capable of providing a high isotacticity tends tohave a molecular weight higher than that those obtained by usingconventional catalysts. Accordingly, it has generally been necessary toadd hydrogen as a chain transfer agent in a large amount to thepolymerization system in order to regulate a molecular weight and a meltflow rate (MFR) of the resulting polymer. Such a large amount ofhydrogen present in the polymerization system, especially when thepropylene is per se used as the polymerization solvent, increases thepressure of polymerization system, so that a polymerization reactor mayneed reinforcing its pressure resistance.

[0010] Propylene block copolymers can be prepared by a multi-steppolymerization (so-called block copolymerization) process whichgenerally comprises initially polymerizing propylene to form apolypropylene component and then copolymerizing ethylene and an α-olefinto form a rubber component. If this polymerization process is carriedout continuously (or in one batch) using the above-mentioned catalystcapable of providing a high isotacticity, a large amount of hydrogengives rise to a problem. That is, the hydrogen added in the initial stepto prepare the polypropylene component remains unreacted in a largeamount and then, in the subsequent step, prevents the rubber componentfrom attaining a high molecular weight (instrinsic viscosity [ ].

[0011] Accordingly, it has been desired that a catalyst system used forthe preparation of a polypropylene and a propylene block copolymer bedeveloped, which makes it possible not only to readily regulate themolecular weight and the melt flow rate (MFR) of the resulting polymersusing a small amount of hydrogen, but also provide a high isotacticityfor the resulting polypropylene and the propylene component of theresulting propylene block copolymer.

[0012] Further, it has also been desired that a process for preparing apropylene block copolymer by which the molecular-weight and the meltflow rate (MFR) of the resulting copolymer can be easily regulated evenwith a small amount of hydrogen, isotacticity of a polypropylenecomponent in the resulting copolymer can be heightened, and a molecularweight of a rubber component in the resulting copolymer can also beincreased.

OBJECT OF THE INVENTION

[0013] The present invention has been made in the light of the foregoingprior art technique, and it is an object of the invention to provideolefin polymerization catalysts by the use of which the molecular weightand the melt flow rate (MFR) of the resulting polypropylene can beeasily regulated even with a small amount of hydrogen and highlyisotactic polypropylene can be prepared, and to provide processes forpreparing polypropylene using said olefin polymerization catalysts.

[0014] It is another object of the invention to provide processes forpreparing a propylene block copolymer by which the molecular weight andthe melt flow rate (MFR) of the resulting copolymer can be easilyregulated even with a small amount of hydrogen, isotacticity of thepolypropylene component in the resulting copolymer can be heightened,and the molecular weight of the rubber composition in the resultingcopolymer can also be increased.

SUMMARY OF THE INVENTION

[0015] The olefin polymerization catalyst (1) according to the inventionis a novel catalyst and formed from:

[0016] [I-1] a contact product obtained by contacting:

[0017] (A) a solid titanium catalyst component comprising magnesium,titanium, halogen and an electron donor,

[0018] (B) an organometallic compound catalyst component, and

[0019] (C) an organosilicon compound represented by the followingformula (c-i)

R^(a) _(n)Si (OR^(b))_(4−n)  (c-i)

[0020] wherein n is 1, 2 or 3; when n is 1, Ra is a secondary ortertiary hydrocarbon group; when n is 2 or 3, at least one of R^(a) is asecondary or tertiary hydrocarbon group, and plural R^(a) may be thesame or different; R^(b) is a hydrocarbon group of 1 to 4 carbon atoms;and when 4-n is 2 or 3, plural OR^(b) may be the same or different;

[0021] [II-1] (D) a compound having at least two ether linkages spacedby plural atoms; and optionally,

[0022] [III] an organometallic compound catalyst component.

[0023] The contact product [I-1] in the catalyst (1) may be replaced bya prepolymerized catalyst component [Ia-1] which is obtained byprepolymerizing an olefin of 2 or more carbon atoms in the presence ofthe catalyst components for forming the contact product [I-1] in such away that the amount of the prepolymer formed is 0.01 to 2,000 g based on1 g of the solid titanium catalyst component (A).

[0024] The olefin polymerization catalyst (2) according to the inventionis formed from:

[0025] [1-2] a contact product obtained by contacting:

[0026] (A) a solid titanium catalyst component,

[0027] (B) an organometallic compound catalyst component, and

[0028] (D) compound having at least two ether linkages spaced by pluralatoms;

[0029] [II-2] (C) an organosilicon compound represented by the aboveformula (c-i); and optionally,

[0030] [III] an organometallic compound catalyst component.

[0031] The contact product [I-2] in the catalyst (2) may be replaced bya prepolymerized catalyst component [Ia-2] which is obtained byprepolymerizing an olefin of 2 or more carbon atoms in the presence ofthe catalyst components for forming the contact product [I-2] in such away that the amount of the prepolymer formed is 0.01 to 2,000 g based on1 g of the solid titanium catalyst component (A).

[0032] The process for preparing a polypropylene according to theinvention comprises polymerizing propylene in the presence of theabove-mentioned olefin polymerization catalyst (1) or (2).

[0033] The polypropylene prepared by the process of the inventionpreferably has the following properties:

[0034] (i) a boiling heptane-insoluble component is contained in saidpolypropylene in an amount of not less than 80% by weight,

[0035] a pentad isotacticity [M_(g)] of the boiling heptane-insolublecomponent determined by the following formula (1) using a ¹³C-NMRspectrum is not less than 0.97: $\begin{matrix}{\left\lbrack M_{5} \right\rbrack = \frac{\lbrack{Pmmmm}\rbrack}{\lbrack{Pw}\rbrack - {2\left( {\left\lbrack {S\quad {\alpha\gamma}} \right\rbrack + \left\lbrack {S\quad {\alpha\delta}^{+}} \right\rbrack} \right)} + {3\left\lbrack {T\quad \delta^{+}\delta^{+}} \right\rbrack}}} & (1)\end{matrix}$

[0036] wherein

[0037] [Pmmmm] is absorption intensity of methyl groups an thirdpropylene units in five propylene unit sequences where the five unitsare bonded isotactically to each other,

[0038] [Pw] is absorption intensity of all methyl groups in propyleneunits,

[0039] [Sαγ] is absorption intensity of secondary carbons in a mainchain, with the proviso that one of two tertiary carbons nearest to eachof said secondary carbons is situated at the α position and the other issituated at the γ position,

[0040] [Sαδ⁺] is absorption intensity of secondary carbons in a mainchain, with the proviso that one of two tertiary carbons nearest to eachof said secondary carbons is situated at the α position and the other issituated at the δ or farther position, and

[0041] [Tδ⁺δ⁺] is absorption intensity of tertiary carbons in a mainchain, with the proviso that one of two tertiary carbons nearest to eachof said tertiary carbons is situated at the δ or farther position andthe other is also situated at the δ or farther position;

[0042] a pentad tacticity [M₃] of the boiling heptane-insolublecomponent determined by the following formula (2) using a ¹³C-NMRspectrum is in the range of 0.0020 to 0.0050: $\begin{matrix}{\left\lbrack M_{3} \right\rbrack = \frac{\begin{matrix}{\lbrack{Pmmrm}\rbrack + \lbrack{Pmrmr}\rbrack + \lbrack{Pmrrr}\rbrack + \lbrack{Prmrr}\rbrack +} \\{\lbrack{Prmmr}\rbrack + \lbrack{Prrrr}\rbrack}\end{matrix}}{\lbrack{Pw}\rbrack - {2\left( {\left\lbrack {S\quad {\alpha\gamma}} \right\rbrack + \left\lbrack {S\quad {\alpha\delta}^{+}} \right\rbrack} \right)} + {3\left\lbrack {T\quad \delta^{+}\delta^{+}} \right\rbrack}}} & (2)\end{matrix}$

[0043] wherein [Pw], [Sαγ], [Sαδ⁺] and [Tδ⁺δ⁺] have the meanings asdefined in the formula (1),

[0044] [Pmmrm] is absorption intensity of methyl groups on thirdpropylene units in five propylene unit sequences represented by ┘ ┘ ┘ ┌┌ in which ┘ and ┌ are each a propylene unit,

[0045] [Pmrmr] is absorption intensity of methyl groups on thirdpropylene units in five propylene unit sequences represented by ┘ ┘ ┐ ┐┘ in which ┘ and ┐ are each a propylene unit,

[0046] [Pmrrr] is absorption intensity of methyl groups on thirdpropylene units in five propylene unit sequences represented by ┘ ┘ ┐ ┘┐ in which ┘ and ┐ are each a propylene unit,

[0047] [Prmrr] is absorption intensity of methyl groups on thirdpropylene units in five propylene unit sequences represented by ┐ ┘ ┘ ┐┘ in which ┘ and ┐ are each a propylene unit,

[0048] [Prmmr] is absorption intensity of methyl groups on thirdpropylene units in five propylene unit sequences represented by ┐ ┘ ┘ ┘┐ in which ┘ and ┐ are each a propylene unit,

[0049] [Prrrr] is absorption intensity of methyl groups on thirdpropylene units in five propylene unit sequences represented by ┘ ┐ ┘ ┐┘ in which ┘ and ┐ are each a propylene unit.

[0050] The first process for preparing a propylene block copolymeraccording to the invention comprises the steps of polymerizing propyleneto form a polypropylene component and copolymerizing ethylene and anα-olefin of 3 to 20 carbon atoms to form an ethylene/α-olefin copolymercomponent, in optional order, wherein both of the polymerizing andcopolymerizing steps are carried out in the presence of theabove-mentioned olefin polymerization catalyst (1).

[0051] The second process for preparing a propylene block copolymeraccording to the invention comprises steps of polymerizing propylene toform a polypropylene component and copolymerizing ethylene and anα-olefin of 3 to 20 carbon atoms to form an ethylene/α-olefin copolymercomponent,in optional order, wherein both of the polymerizing andcopolymerizing steps are carried out in the presence of theabove-mentioned olefin polymerization catalyst (2).

[0052] The third process for preparing a propylene block copolymeraccording to the invention comprises steps of polymerizing propylene toform a polypropylene component and copolymerizing ethylene and anα-olefin of 3 to 20 carbon atoms to form an ethylene/α-olefin copolymercomponent, in optional order, wherein both of the polymerizing andcopolymerizing steps are carried out in the presence of an olefinpolymerization catalyst (3) formed from:

[0053] [I-3] a contact product obtained by contacting:

[0054] (A) a solid titanium catalyst component,

[0055] (B) an organometallic compound catalyst component, andoptionally,

[0056] (D) a compound having at least two ether linkages spaced pluralatoms;

[0057] (D) a compound having at least two ether linkages spaced byplural atoms; and optionally,

[0058] [II-3]

[0059] [III] an organometallic compound catalyst component.

[0060] In the third process for preparing a propylene block copolymeraccording to the invention, the contact product [I-3] in the catalyst(3) may be replaced by a prepolymerized catalyst component [Ia-3] whichis obtained by prepolymerizing an olefin of 2 or more carbon atoms inthe presence of the catalyst components for forming the contact product[I-3] in such a way that the amount of the prepolymer formed is 0.01 to2,000 g based on 1 g of the solid titanium catalyst component (A).

[0061] The fourth process for preparing a propylene block copolymeraccording to the invention comprises steps of polymerizing propylene toform a polypropylene component and copolymerizing ethylene and anα-olefin of 3 to 20 carbon atoms to form an ethylene/α-olefin copolymercomponent, in optional order, wherein both of the polymerizing andcopolymerizing steps are carried out in the presence of an olefinpolymerization catalyst (4) formed from:

[0062] [I-4] (A-2) a solid titanium catalyst component comprisingmagnesium, titanium, halogen and (D) a compound having at least twoether linkages spaced by plural atoms;

[0063] [11-4] (C) an organosilicon compound represented by the aboveformula (c-i) and/or (D) a compound having at least two ether linkagesspaced by plural atoms; and.

[0064] [III] an organometallic compound catalyst component.

[0065] In the fourth process for preparing a propylene block copolymer,the olefin polymerization catalyst (4) may be replaced by an olefinpolymerization catalyst (4a) formed from:

[0066] [Ia-4] a prepolymerized catalyst component obtained byprepolymerizing an olefin of 2 or more carbon atoms in the presence of

[0067] (A-2) a solid titanium catalyst component containing magnesium,titanium, halogen and (D) a compound having at least two ether linkagesspaced by plural atoms, and

[0068] (B) an organometallic compound catalyst component,

[0069] in such a way that the amount of the prepolymer formed is 0.01 to2,000 g based on 1 g of the solid titanium catalyst component (A-2);

[0070] [II-4] (C) an organosilicon compound represented by the aboveformula (c-i) and/or (D) the compound having at least two ether linkagesspaced by plural atoms; and optionally,

[0071] [III] the organometallic compound catalyst component.

[0072] The fifth process for preparing a propylene block copolymeraccording to the invention comprises steps of polymerizing propylene toform a polypropylene component and copolymerizing ethylene and anα-olefin of 3 to 20 carbon atoms to form an ethylene/α-olefin copolymercomponent, in an optional order, wherein both of the polymerizing andcopolymerizing steps are carried out in the presence of an olefinpolymerization catalyst (5a) formed from:

[0073] [Ia-5] a prepolymerized catalyst component which is obtained byprepolymerizing an olefin of 2 or more carbon atoms in the presence of

[0074] (A) a solid titanium catalyst,

[0075] (B) an organometallic compound catalyst component, and

[0076] (E) an organosilicon compound represented by the followingformula (c-iii)

R_(n)Si(OR′)_(4−n)  (c-iii)

[0077] wherein R and R′ are each a hydrocarbon group, and n is a numbersatisfying the condition of 0<n <4;

[0078] in such a way that the amount of the prepolymer formed is 0.01 to2,000 g based on 1 g of the following solid titanium catalyst component(A)

[0079] [II-5] (C) an organosilicon compound represented by the aboveformula (c-i); and optionally,

[0080] [III] an organometallic compound catalyst component.

[0081] In the present invention, the compound (D) having at least twoether linkages spaced by plural atoms is preferably represented by thefollowing formula:

[0082] wherein n is an integer satisfying the condition of 2≦n≦10; R²¹to R²⁶ are each a substituent having at least one atom selected from thegroup consisting of carbon, hydrogen, oxygen, halogen, nitrogen, sulfur,phosphorus, boron and silicon; any optional combination of from R¹ toR²⁶, preferably from R¹ to R^(2n), may form together a ring other than abenzene ring; and the main chain of the compound may contain atoms otherthan carbon.

[0083] In the present invention, the organosilicon compound (C) ispreferably represented by the following formula (c-ii):

[0084] wherein R^(a) and R^(c) are each independently a cyclopentylgroup, a substituted cyclopentyl group, a cyclopentenyl group, asubstituted cyclopentenyl group, a cyclopentadienyl group, a substitutedcyclopentadienyl group or a hydrocarbon group whose carbon adjacent toSi is secondary or tertiary carbon.

[0085] According to the processes for preparing a propylene blockcopolymer of the invention, a propylene block copolymer having thefollowing properties can be prepared.

[0086] (i) A boiling heptane-insoluble component in the propylene blockcopolymer has a pentad isotacticity [M_(g)], obtained from the aboveformula (1) using a ¹³C-NMR spectrum, of not less than 0.97 , and has apentad tacticity [M_(g)], obtained from the above formula (2) using a¹³C-NMR spectrum, of 0.0020 to 0.0050.

[0087] (ii) A 23° C. n-decane-soluble component in the propylene blockcopolymer has an intrinsic viscosity [η], as measured indecahydronaphthalene at 135° C., of not less than 2 dl/g.

BRIEF DESCRIPTION OF THE DRAWINGS

[0088]FIG. 1 is given to illustrate an exmple of steps of a process forpreparing a novel olefin polymerization catalyst (1) or (1 a) accordingto the invention.

[0089]FIG. 2 is given to illustrate an exmaple of steps of a process forpreparing a novel olefin polymerization catalyst (2) or (2 a) accordingto the invention.

[0090]FIG. 3 is given to illustrate an exmaple of steps of a process forpreparing an olefin polymerization catalyst which is used in the thirdprocess for preparing a propylene block copolymer according to theinvention, together with steps of a process for preparing a propyleneblock copolymer using said catalyst.

[0091]FIG. 4 is given to illustrate an example of steps of a process forpreparing an olefin polymerization catalyst which is used in the fourthprocess for preparing a propylene block copolymer according to theinvention, together with steps of a process for preparing a propyleneblock copolymer using said catalyst.

[0092]FIG. 5 is given to illustrate an example of steps of a process forpreparing an olefin polymerization catalyst which is used in the fifthprocess for preparing a propylene block copolymer according to theinvention, together with steps of a process for preparing a propyleneblock copolymer using said catalyst.

DETAILED DESCRIPTION OF THE INVENTION

[0093] The novel olefin polymerization catalysts according to theinvention, the processes for preparing a polypropylene or a propyleneblock copolymer using said catalysts, and the processes for preparing apropylene block copolymer using specific catalysts according to theinvention will be described in detail hereinafter.

[0094] The meaning of the term “polymerization” used herein is notlimited to “homopolymerization” but may comprehend “copolymerization”.Also, the meaning of the term “polymer” used herein is not limited to“homopolymer” but may comprehend “copolymer”.

[0095] The novel olefin polymerization catalysts according to theinvention are first described.

[0096] The olefin polymerization catalyst (1) according to the inventionis formed from:

[0097] [I-1] a contact product obtained by contacting:

[0098] (A) a solid titanium catalyst component comprising magnesium,titanium, halogen and an electron donor,

[0099] (B) an organometallic compound catalyst component, and

[0100] (C) an organosilicon compound represented by the followingformula (c-i):

R^(a) _(n)Si(OR^(b))_(4−n)  (c-i)

[0101] wherein n is 1, 2 or 3; when n is 1, R^(a) is a secondary ortertiary hydrocarbon group; when n is 2 or 3, at least one of R^(a) is asecondary or tertiary hydrocarbon group, and plural R^(a) may be thesame or different; R^(b) is a hydrocarbon group of 1 to 4 carbon atoms;and when 4−n is 2 or 3, plural OR^(b) may be the same or different;

[0102] [II-1] (D) a compound having at least two ether linkages spacedby plural atoms; and optionally,

[0103] [III] an organometallic compound catalyst component.

[0104] The contact product [I-1] in the catalyst (1) may be replaced bya prepolymerized catalyst component [Ia-1] which is obtained byprepolymerizing an olefin of 2 or more carbon atoms in the presence ofthe catalyst components for forming the contact product [I-1] in such away that the amount of the prepolymer formed is 0.01 to 2,000 g based on1 g of the solid titanium catalyst component (A).

[0105] In more detail, the olefin polymerization catalyst (1 a)according to the invention is formed from:

[0106] [Ia-1] a prepolymerized catalyst component which is obtained byprepolymerizing an olefin of 2 or more carbon atoms in the presence ofthe catalyst components for forming the contact product [I-1] in such away that the amount of the prepolymer formed is 0.01 to 2,000 g based on1 g of the solid titanium catalyst component (A);

[0107] [II-1] (D) the polyether compound; and optionally,

[0108] [III] the organometallic compound catalyst component.

[0109]FIG. 1 is given to illustrate an example of steps of a process forpreparing the olefin polymerization catalyst (1) or (1 a) of theinvention.

[0110] The olefin polymerization catalyst (2) according to the inventionis formed from:

[0111] [I-2] a contact product obtained by contacting:

[0112] (A) a solid titanium catalyst component,

[0113] (B) an organometallic compound catalyst component, and

[0114] (D) an compound having at least two ether linkages spaced byplural atoms;

[0115] [II-2] (C) an organosilicon compound represented by the aboveformula (c-i); and optionally,

[0116] [III] an organometallic compound catalyst component.

[0117] The olefin polymerization catalyst (2a) according to theinvention is formed from:

[0118] [Ia-2] a prepolymerized catalyst which is obtained byprepolymerizing an olefin of 2 or more carbon atoms in the presence ofthe catalyst components for forming the contact product [I-1] in such away that the amount of the prepolymer formed is 0.01 to 2,000 g based on1 g of the solid titanium catalyst component (A).

[0119] [II-2] (C) the organosilicon compound represented by the aboveformula (c-i); and optionally,

[0120] [III] the organometallic compound catalyst component.

[0121]FIG. 2 is given to illustrate an example of steps of a process forpreparing the olefin polymerization catalyst (2) or (2 a) of theinvention.

[0122] Each of the components for forming the olefin polymerizationcatalysts of the invention is described below in detail.

(A) Solid Titanium Catalyst Component

[0123] The solid titanium catalyst component (A) can be prepared bybringing a magnesium compound, a titanium compound and an electron donordescribed below into contact with each other.

[0124] The titanium compound used for preparing the solid titaniumcatalyst component (A) includes, for example, tetravalent titaniumcompounds represented by the following formula:

[0125] Ti(OR)_(g)X_(4−g)

[0126] wherein R is a hydrocarbon group, X is a halogen atom, and g is anumber satisfying the condition of 0≦g≦4.

[0127] Specifically, the titanium compounds include:

[0128] titanium tetrahalides, such as TiCl₁, TiBr₄ and TiI₄;

[0129] alkoxytitanium trihalides, such as Ti(OCH₃)Cl₃,

[0130] Ti(OC₂H₅) Cl₃, Ti(O-n-C₄H₉)Cl₃, Ti(OC₂H₅)Br₃ and Ti(O-iso-C₄H₉)Br₃;

[0131] dialkoxytitanium dihalides, such as Ti(OCH₃)₂Cl₂, Ti(OC₂H₅)₂Cl₂,Ti(O-n-C₄H₉)₂Cl₂ and Ti(OC₂H₅)₂Br₂;

[0132] trialkoxytitanium monohalides, such as Ti(OCH₃)₃Cl, Ti(OC₂H₅)₃Cl,Ti(O-n-C₄H₉)₃Cl and Ti(OC₂H₅)₃Br; and

[0133] tetraalkoxytitaniums, such as Ti(OCH₃)₄, Ti (OC₂H₅)₄,Ti(O-n-C₄H₉)₄, Ti(O-iso-C₄H₉)₄ and Ti(O-2-ethylhexyl).

[0134] Of these, preferred are halogen-containing compounds, morepreferred are titanium tetrahalides, and particularly preferred istitanium tetrachloride. These titanium compounds may be used singly orin combination. Further, they may be diluted with hydrocarbon compoundsor halogenated hydrocarbon compounds.

[0135] The magnesium compound used for preparing the solid titaniumcatalyst component (A) includes those having reducing property as wellas those not having reducing property.

[0136] The magnesium compound having reducing property may have amagnesium-to-carbon bond or a magnesium-to-hydrogen bond. Specifically,the magnesium compounds having reducing property includedimethylmagnesium, diethylmagnesium, dipropylmagnesium,dibutylmagnesium, diamylmagnesium, dihexylmagnesium, didecylmagnesium,ethylmagnesium chloride, propylmagnesium chloride, butylmagnesiumchloride, hexylmagnesium chloride, amylmagnesium chloride,butylethoxylmagnesium, ethylbutylmagnesium and butylmagnesium hydride.These magnesium compounds may be used singly or in combination, or maybe used in the form of complex compounds with organometallic compoundsdescribed later. Further, these magnesium compounds may be liquid orsolid, and may be derived by the reaction of metallic magnesium with acorresponding compound. Furthermore, they may be derived from metallicmagnesium during the preparation of the catalyst using the above method.

[0137] Examples of the magnesium compounds not having reducing propertyinclude magnesium halides such as magnesium chloride, magnesium bromide,magnesium iodide and magnesium fluoride; alkoxymagnesium halides such asmethoxymagnesium chloride, ethoxymagnesium chloride, isopropoxymagnesiumchloride, butoxymagnesium chloride and octoxymagnesium chloride;aryloxymagnesium halides such as phenoxymagnesium chloride andmethylphenoxymagnesium chloride; alkoxymagnesiums such asethoxymagnesium, isopropoxymagnesium, butoxymagnesium, n-octoxymagnesiumand 2-ethylhexoxymagnesium; aryloxymagnesiums such as phenoxymagnesiumand dimethylphenoxymagnesium; and magnesium carboxylates such asmagnesium laurate and magnesium stearate.

[0138] These magnesium compounds not having reducing property may bethose derived from the above-mentioned magnesium compounds havingreducing property or those derived during the preparation of thecatalyst component. In order to derive the magnesium compound not havingreducing property, the magnesium compound having reducing property maybe brought into contact with a halogen or a compound having an activecarbon-to-oxygen bond such as a polysiloxane compound, ahalogen-containing silane compound, a halogen-containing aluminumcompound, alcohol, ester, ketone and aldehyde.

[0139] Besides those magnesium compounds mentioned above, there can beused complex compounds or double compounds of these magnesium compoundswith other metals, or mixtures of these magnesium compounds with othermetallic compounds. The magnesium compounds may be used in combinationof two or more kinds.

[0140] Various magnesium compounds other than those mentioned above canalso be used for preparing the solid titanium catalyst component (A),but it is preferred that the magnesium compound is present in the formof a halogen-containing magnesium compound in the solid titaniumcatalyst component (A) finally obtained. Accordingly, if a magnesiumcompound not containing halogen is used, the compound is preferablybrought into contact with a halogen-containing compound in the course ofthe catalyst preparation.

[0141] Of the above-mentioned magnesium compounds, preferred aremagnesium compounds not having reducing property. More preferred arehalogen-containing magnesium compounds. Particularly preferred aremagnesium chloride, alkoxymagnesium chloride and aryloxymagnesiumchloride.

[0142] The solid titanium catalyst component (A) used in the inventionis formed by bringing such a magnesium compound as mentioned above intocontact with the aforesaid titanium compound and an electron donor (a).

[0143] Examples of the electron donor (a) used for preparing the solidtitanium catalyst component (A) include alcohols, phenols, ketones,aldehydes, carboxylic acids, halides of organic acids, and ethers,esters, amides or anhydrides of organic and inorganic acids, ammonia,amines, nitriles, isocyanates, nitrogen-containing cyclic compounds andoxygen-containing cyclic compounds, excepting the polyether compounds(D) as described later.

[0144] Specifically, the electron donor compounds include:

[0145] alcohols of 1 to 18 carbon atoms, such as methanol, ethanol,propanol, pentanol, hexanol, octanol, 2-ethylhexanol, dodecanol,octadecyl alcohol, oleyl alcohol, benzyl alcohol, phenylethyl alcohol,cumyl alcohol, isopropyl alcohol and isopropylbenzyl alcohol;

[0146] halogen-containing alcohols of 1-18 carbon atoms such astrichloromethanol, trichloroethanol and trichlorohexanol;

[0147] phenols of 6 to 20 carbon atoms which may have lower alkyl group,such as phenol, cresol, xylenol, ethylphenol, propylphenol, nonylphenol,cumylphenol and naphthol;

[0148] ketones of 3 to 15 carbon atoms, such as acetone, methyl ethylketone, methyl isobutyl ketone, acetophenone, benzophenone,acetylacetone and benzoquinone;

[0149] aldehydes of 2 to 15 carbon atoms, such as acetaldehyde,propionaldehyde, octylaldehyde, benzaldehyde, tolualdehyde andnaphthaldehyde;

[0150] organic esters of 2 to 30 carbon atoms, such as methyl formate,methyl acetate, ethyl acetate, vinyl acetate, propyl acetate, octylacetate, cyclohexyl acetate, ethyl propionate, methyl butyrate, ethylvalerate, methyl chloroacetate, ethyl dichloroacetate, methylmethacrylate, ethyl crotonate, ethyl cyclohexanecarboxylate, methylbenzoate, ethyl benzoate, propyl benzoate, butyl benzoate, octylbenzoate, cyclohexyl benzoate, phenyl benzoate, benzyl benzoate, methyltoluate, ethyl toluate, amyl toluate, ethyl ethylbenzoate, methylanisate, n-butyl maleate, diisobutyl methylmalonate, di-n-hexylcyclohexenecarboxylate, diethyl nadiate, diisopropyltetrahydrophthalate, diethyl phthalate, diisobutyl phthalate, di-n-butylphthalate, di-2-ethylhexyl phthalate, γ-butyrolactone, δ-valerolactone,coumarin, phthalide and ethyl carbonate;

[0151] ethers of 2 to 20 carbon atoms, such as methyl ether, ethylether, isopropyl ether, butyl ether, amyl ether, anisole and diphenylether epoxy-p-menthane;

[0152] acid amides such as N,N-dimethylacetamide, N,N-dimethylbenzamideand N,N-dimethyltoluamide;

[0153] amines, such as methylamine, ethylamine, dimethylamine,diethylamine, ethylenediamine, tetramethylenediamine,hexamethylenediamine, tributylamine and tribenzylamine;

[0154] nitriles such as acetonitrile, benzonitrile and trinitrile;

[0155] acid anhydrides, such as acetic anhydrides, phthalic anhydrideand benzoic anhydride;

[0156] pyrroles, such as pyrrole, methylpyrrole and dimethylpyrrole;

[0157] pyrroline;

[0158] pyrrolidine;

[0159] indole;

[0160] pyridines, such as pyridine, methylpyridine, ethylpyridine,propylpyridine, dimethylpyridine, ethylmethylpyridine,trimethylpyridine, phenylpyridine, benzylpyridine and pyridine chloride;

[0161] nitrogen-containing cyclic compounds, such as piperidines,quinolines and isoquinolines;

[0162] oxygen-containing cyclic compounds, such as tetrahydrofuran,1,4-cineol, 1,8-cineol, pinolfuran, methylfuran, dimethylfuran,diphenylfuran, benzofuran, coumaran, phthalan, tetrahydropyran, pyranand dihydropyran.

[0163] Other than those compounds, water and surface active agents ofanionic type, cationic type and nonionic type can be employed.

[0164] Further, particularly preferred examples of the organic estersare polycarboxylic esters having skeletons represented by the followingformulas:

[0165] In the above formulas, R is a substituted or unsubstitutedhydrocarbon group, R², R⁵ and R⁶ are each hydrogen or a substituted orunsubstituted hydrocarbon group, and R³ and R⁴ are each hydrogen or asubstituted or unsubstituted hydrocarbon group, preferably at least oneof R³ and R⁴ being a substituted or unsubstituted hydrocarbon group. R³and R⁴ may be linked to each other to form a cyclic structure. When anyof the hydrocarbon groups indicated by R¹ to R⁶ is substituted, thesubstituent group contains a heteroatom such as N, O or S, and it has agroup such as C—O—C, COOR, COCH, OH, SO₃H, —C—N—C— or NH₂.

[0166] Examples of the polycarboxylic esters include:

[0167] aliphatic polycarboxylic esters, such as diethyl succinate,dibutyl succinate, diethyl methylsuccinate, diisobutylα-methylglutarate, diethyl methylmalonate, diethyl ethylmalonate,diethyl isopropylmalonate, diethyl butylmalonate, diethylphenylmalonate, diethyl diethylmalonate, diethyl dibutylmalonate,monooctyl maleate, dioctyl maleate, dibutyl maleate, dibutylbutylmaleate, diethyl butylmaleate, diisopropyl β-methylglutarate,diallyl ethylsuccinate, di-2-ethylhexyl fumarate, diethyl itaconate anddioctyl citraconate;

[0168] alicyclic polycarboxylic esters, such as diethyl1,2-cyclohexanecarboxylate, diisobutyl 1,2-cyclohexanecarboxylate,diethyl tetrahydrophthalate and diethyl nadiate;

[0169] aromatic polycarboxylic esters, such as monoethyl phthalate,dimethyl phthalate, methylethyl phthalate, monoisobutyl phthalate,diethyl phthalate, ethylisobutyl phthalate, di-n-propyl phthalate,diisopropyl phthalate, di-n-butyl phthalate, diisobutyl phthalate,di-n-heptyl phthalate, di-2-ethylhexyl phthalate, di-n-octyl phthalate,dineopentyl phthalate, didecyl phthalate, benzylbutyl phthalate,diphenyl phthalate, diethyl naphthalenedicarboxylate, dibutylnaphthalenedicarboxylate, triethyl trimellitate and dibutyltrimellitate; and

[0170] heterocyclic polycarboxylic esters, such as3,4-furandicarboxylate.

[0171] Other examples of the polycarboxylic esters are esters of longchain dicarboxylic acids, such as diethyl adipate, diisobutyl adipate,diisopropyl sebacate, di-n-butyl sebacate, di-n-octyl sebacate anddi-2-ethylhexyl sebacate.

[0172] Of the above compounds, preferably used as the electron donor (a)in the invention are carboxylic esters, more preferably used arepolycarboxylic esters, and particularly preferably used are phthalicesters.

[0173] These compounds can be used in combination of two or more kinds.

[0174] Also employable as the electron donor (a) is a silicon compoundrepresented by the formula (c-iii) described later.

[0175] When the titanium compound, the magnesium compound and theelectron donor are brought into contact with each other, a carriercompound may be used to prepare a solid titanium catalyst component (A)supported on a carrier.

[0176] Examples of the carrier compounds include A1₂03, SiO₂, B₂O₃, MgO,CaO, TiO₂, ZnO, Zn₂O, SnO₂, BaO, ThO and resins such as astyrene/divinylbenzene copolymer. Of these carrier compounds, preferredare SiO₂, Al₂O₃, MgO, ZnO and Zn₂O.

[0177] The above-mentioned components may be contacted in the presenceof other reagents such as silicon, phosphorus and aluminum.

[0178] The solid titanium catalyst component (A) can be prepared bybringing the titanium compound, the magnesium compound and the electrondonor into contact with each other, wherein any one of conventionallyknown processes may be employed.

[0179] Some examples of the known processes for preparing the solidtitanium catalyst component (A) are briefly described below.

[0180] (1) A process comprising contacting a solution consisting of amagnesium compound, an electron donor and a hydrocarbon solvent with atitanium compound after or simultaneously with precipitating a solid bycontacting the solution with an organometallic compound.

[0181] (2) A process comprising contacting a complex composed of amagnesium compound and an electron donor with an organometallic compoundand then contacting the reaction product with a titanium compound.

[0182] (3) A process comprising contacting a reaction product of aninorganic carrier and an organomagnesium compound with a titaniumcompound and preferably together with an electron donor. In thisprocess, the reaction product may be beforehand contacted with ahalogen-containing compound and/or an organometallic compound.

[0183] (4) A process comprising obtaining an inorganic or organiccarrier on which a magnesium compound is supported from a mixture of aninorganic or organic carrier and a solution containing a magnesiumcompound and an electron donor, and optionally a hydrocarbon solvent,and then contacting the resulting carrier with a titanium compound.

[0184] (5) A process comprising contacting a solution containing amagnesium compound and an electron donor, and optionally a hydrocarbonsolvent, with an inorganic or organic carrier to obtain a solid titaniumcatalyst component on which magnesium and titanium are supported.

[0185] (6) A process comprising contacting a liquid organomagnesiumcompound with a halogen-containing titanium compound. In this process,an electron donor is used at least once.

[0186] (7) A process comprising contacting a liquid organomagnesiumcompound with a halogen-containing titanium compound and then contactingthe reaction product with a titanium compound. In this process, anelectron donor is used at least once.

[0187] (8) A process comprising contacting an alkoxy group-containingmagnesium compound with a halogen-containing titanium compound. In thisprocess, an electron donor is used at least once.

[0188] (9) A process comprising contacting a complex composed of analkoxy group-containing magnesium compound and an electron donor with atitanium compound.

[0189] (10) A process comprising contacting a complex composed of analkoxy group-containing magnesium compound and an electron donor with atitanium compound and then contacting the reaction product with atitanium compound.

[0190] (11) A process comprising contacting a magnesium compound, anelectron donor and a titanium compound in an optional order. In thisreaction, each components may be pretreated with an electron donorand/or a reaction assistant such as an organometallic compound or ahalogen-containing silicon compound. In this process, it is preferred touse the electron donor at least once.

[0191] (12) A process comprising contacting a liquid magnesium compoundhaving no reducing ability with a liquid titanium compound, preferablyin the presence of an electron donor, to precipitate a solidmagnesium/titanium complex compound.

[0192] (13) A process comprising further contacting the reaction productobtained in the process (12) with a titanium compound.

[0193] (14) A process comprising further contacting the reaction productobtained in the process (11) or (12) with an electron donor and atitanium compound.

[0194] (15) A process comprising pulverizing a magnesium compound and atitanium compound, and optionally an electron donor, to give a solid andtreating the solid with either halogen, a halogen compound or aromatichydrocarbon.

[0195] This process may include a step of pulverizing only a magnesiumcompound, a step of pulverizing a complex composed of a magnesiumcompound and an electron donor, or a step of pulverizing a magnesiumcompound and a titanium compound. Further, after the pulverization, thesolid may be pretreated with a reaction assistant and then treated withhalogen or the like. Examples of the reaction assistants include anorganometallic compound and a halogen-containing silicon compound.

[0196] (16) A process comprising pulverizing a magnesium compound andthen contacting the pulverized compound with a titanium compound. Inthis process, an electron donor or a reaction assistant is preferablyused in the pulverization stage and/or the contacting stage.

[0197] (17) A process comprising treating the compound obtained in anyof the processes (11) to (16) with halogen, a halogen compound oraromatic hydrocarbon.

[0198] (18) A process comprising contacting the reaction product of ametal oxide, an organomagnesium compound and a halogen-containingcompound with a titanium compound and if necessary an electron donor.

[0199] (19) A process comprising contacting a magnesium compound such asa magnesium salt of organic acid, alkoxymagnesium or aryloxymagnesiumwith a titanium compound and/or halogen-containing hydrocarbon and ifnecessary an electron donor.

[0200] (20) A process comprising contacting a hydrocarbon solutioncontaining at least a magnesium compound and alkoxytitanium with atitanium compound and/or an electron donor. In this process, ahalogen-containing compound such as a halogen-containing siliconcompound is preferably allowed to coexist.

[0201] (21) A process comprising reacting a liquid magnesium compoundhaving no reducing ability with an organometallic compound toprecipitate a solid magnesium/metal (aluminum) complex compound and thencontacting the resulting compound with an electron donor and a titaniumcompound.

[0202] The amounts of each components used for preparing the solidtitanium catalyst component (A) vary depending on the process used, andcannot be defined in general. However, for example, the electron donoris used in an amount of 0.01 to 5 mol, preferably 0.1 to 1 mol, and thetitanium compound is used in an amount of 0.01 to 1,000 mol, preferably0.1 to 200 mol, both based on 1 mol of the magnesium compound.

[0203] The solid titanium catalyst component (A) obtained as abovecontains, as its essential ingredients, magnesium, titanium, halogen andan electron donor.

[0204] In this solid titanium catalyst component (A), an atomic ratio ofhalogen/titanium is about 2 to 200, preferably about 4 to 100; a molarratio of the electron donor/titanium is about 0.01 to 100, preferablyabout 0.2 to 10; and an atomic ratio of magnesium/titanium is about 1 to100, preferably about 2 to 50.

(B) Organometallic Catalyst Component

[0205] As the organometallic catalyst component (B), organometalliccompounds of metals belonging to Group I to III of the periodic tableare employable, and examples thereof include:

[0206] (B-1) organoaluminum compounds represented by the followingformula

[0207] R¹ _(m)Al(OR²)_(n)H_(p)X_(q)

[0208] wherein R¹ and R² are each a hydrocarbon group having usually 1to 15 carbon atoms, preferably 1 to 4 carbon atoms, R¹ and R² my be thesame or different, X is a halogen atom, and m, n, p and q are numberssatisfying the conditions of 0<m≦3, 0≦n<3, 0≦p<3, 0≦q<3 and m+n+p+q=3;

[0209] [B-2] alkyl complex compounds of aluminum and Group I metals,represented by the following formula

[0210] M¹AlR¹ ₄

[0211] wherein M¹ is Li, Na or K, and R¹ is the same as defined above;and

[0212] [B-3] dialkyl compounds of Group II or III metals, represented bythe following formula

[0213] R¹R²M²

[0214] wherein R¹ and R² are the same as defined above, and M² is Mg, Znor Cd.

[0215] Examples of the organoaluminum compounds (B-1) include:

[0216] compounds of the formula R¹ _(m)Al(OR²)_(3−m) wherein R¹ and R²are the same as defined above, and m is preferably a number satisfyingthe condition of 1.5≦m≦3;

[0217] compounds of the formula R_(m)AlX_(3−m) wherein R¹ is the same asdefined above, X is halogen, and m is preferably a number satisfying thecondition of 0<m<3;

[0218] compounds of the formula R¹ _(m)AlH_(3−m) wherein R¹ is the sameas defined above, and m is preferably a number satisfying the conditionof 2≦m<3; and

[0219] compounds of the formula R¹ _(m)Al(OR²)_(n)X_(q) wherein R¹ andR² are the same as defined above, X is halogen, and m, n, and q arenumbers satisfying the conditions of 0<m≦3, 0≦n<3, 0 ≦q<3 and m+n+q=3.

[0220] More specifically, examples of the aluminum compounds (B-1)include:

[0221] trialkylaluminums, such as triethylaluminum and tributylaluminum;

[0222] trialkenylaluminums, such as triisoprenylaluminum;

[0223] dialkylaluminum alkoxides, such as diethylaluminum ethoxide anddibutylaluminum butoxide;

[0224] alkylaluminum sesquialkoxides, such as ethylaluminumsesquiethoxide and butylaluminum sesquibutoxide;

[0225] partially alkoxylated alkylaluminums, such as those having anaverage composition represented by, for example, the formula R¹_(2.5)Al(OR²)_(0.5);

[0226] dialkylaluminum halides, such as diethylaluminum chloride,dibutylaluminum chloride and diethylaluminum bromide;

[0227] alkylaluminum sesquihalides, such as ethylaluminumsesquichloride, butylaluminum sesquichloride and ethylaluminumsesquibromide;

[0228] partially halogenated alkylaluminums, such as alkylaluminumdihalides, e.g., ethylaluminum dichloride, propylaluminum dichloride andbutylaluminum dibromide;

[0229] dialkylaluminum hydrides, such as diethylaluminum hydride anddibutylaluminum hydride;

[0230] partially hydrogenated alkylaluminums, such as alkylaluminumdihydrides, e.g., ethylaluminum dihydride and propylaluminum dihydride;and

[0231] partially alkoxylated and halogenated alkylalumiums, such asethylaluminum ethoxychloride, butylaluminum butoxychloride andethylaluminum ethoxybromide.

[0232] Analogues to the aluminum compound (B-1) are organoaluminumcompounds in which at least two aluminum atoms are linked to each otherthrough an oxygen atom or a nitrogen atom.

[0233] Examples of such compounds include:

[0234] (C₂H₅)₂AlOAl(C₂H₅)₂,

[0235] (C₄H₉)₂AlOAl(C₄H₉)₂,

[0236] (C₂H₅)₂AlN(C₂H₅)Al(C₂H₅)₂, and

[0237] aluminoxanes such as methylaluminoxane.

[0238] The compounds belonging to the compound (B-2) are, for example,LiAl(C₂H₅)₄ and LiAl(C₇H₁₅)₄.

[0239] Of the above compounds, organoaluminum compounds are preferablyemployed.

(C) Organosilicon Compound

[0240] The organosilicon compound (C) is the compound represented by thefollowing formula (c-i);

R^(a) _(n)—Si—(OR^(b))_(4−n)  (c-i)

[0241] wherein, n is 1, 2 or 3; when n is 1, R^(a) is a secondary or atertiary hydrocarbon group; when n is 2 or 3, at least one of R^(a) is asecondary or a tertiary hydrocarbon group, R^(a) may be the same ordifferent; and R^(b) is a hydrocarbon group of 1 to 4 carbon atoms; andwhen 4−n is 2 or 3, OR^(b) may be the same or different.

[0242] In the organosilicon compound represented by the formula (c-i),the secondary or the tertiary hydrocarbon group includes cyclopentyl,cyclopentenyl and cyclopentadienyl, and substituted thereof, and thehydrocarbon group in which the carbon adjacent to Si is a secondary ortertiary.

[0243] More specifically, the substituted cyclopentyl group includescyclopentyl group having alkyl group such as 2-methylcyclopentyl,3-methylcyclopentyl, 2-ethylcyclopentyl, 2-n-butylcyclopentyl,2,3-dimethylcyclopentyl, 2,4-dimethylcyclopentyl,2,5-dimethylcyclopentyl, 2,3-diethylcyclopentyl,2,3,4-trimethylcyclopentyl, 2,3,5-trimethylcyclopentyl,2,3,4-triethylcyclopentyl, tetramethylcyclopentyl andtetraethylcyclopentyl;

[0244] the substituted cyclopentenyl group includes cyclopentenyl grouphaving alkyl group such as 2-methylcyclopentenyl, 3-methylcyclopentenyl,2-ethylcyclopentenyl, 2-n-butylcyclopentenyl, 2,3-dimethylcyclopentenyl,2,4-dimethylcyclopentenyl, 2,5-dimethylcyclopentenyl,2,3,4-trimethylcyclopentenyl, 2,3,5-trimethylcyclopentenyl,2,3,4-triethylcyclopentenyl, tetramethylcyclopentenyl andtetraethylcyclopentenyl;

[0245] the substituted cyclopentadienyl group includes cyclopentadienylgroup having alkyl group such as 2-methylcyclopentadienyl,3-methylcyclopentadienyl, 2-ethylcyclopentadienyl,2-n-butylcyclopentadienyl, 2,3-dimethylcyclopentadienyl,2,4-dimethylcyclopentadienyl, 2,5-dimethylcyclopentadienyl,2,3-diethylcyclopentadienyl, 2,3,4-trimethylcyclopentadienyl,2,3,5-trimethylcyclopentadienyl, 2,3,4-triethylcyclopentadienyl,2,3,4,5-tetramethylcyclopentadienyl, 2,3,4,5-tetraethylcyclopentadienyl,1,2,3,4,5-pentamethylcyclopentadienyl and1,2,3,4,5-pentaethylcyclopentadienyl.

[0246] The hydrocarbon group in which the carbon adjacent to Si is asecondary includes 1-propyl, s-butyl, s-amyl and α-benzyl; and

[0247] the hydrocarbon group in which the carbon adjacent to Si is atertiary includes t-butyl, t-amyl, α,α′-diemethylbenzyl and admantyl.

[0248] When n is 1, the organosilicon compound represented by theformula (c-i) includes trialkoxysilanes such ascyclopentyltrimethoxysilane, 2-methylcyclopentyltrimethoxysilane,2,3-dimethylcyclopentyltrimethoxysilane, cyclopentyltriethoxysilane,iso-butyltriethoxysilane, t-butyltriethoxysilane,cyclohexyltrimethoxysilane, cyclohexyltriethoxysilane,2-norbornanetrimethoxysilane, and 2-norbornanetriethoxysilane;

[0249] when n is 2, the organosilicon compound represented by theformula (c-i) includes dialkoxysilanes such asdicyclopentyldiethoxysilane, t-butylmethyldimethoxysilane,t-butylmethyldiethoxysilane, t-amylmethyldiethoxysilane,dicyclohexyldimethoxysilane, cyclohexylmethyldimethoxysilane,cyclohexylmethyldiethoxysilane, and 2-norbornanemethyldimethoxysilane.

[0250] When n is 2, the organosilicon compound represented by theformula (c-i) is preferably dimethoxy compound represented by thefollowing formula (c-ii);

[0251] wherein, R^(a) and R^(c) are each independently a cyclopentylgroup, a substituted cyclopentenyl group, a cyclopentadienyl group, asubstituted cyclopentadienyl group or a hydrocarbon group whose carbonadjacent to Si is a secondary carbon or a tertiary carbon.

[0252] The organosilicon compound represented by the formula (c-ii)includes, for example, dicyclopentyldimethoxysilane,dicyclopentenyldimethoxyxilane, dicyclopentadienyldimethoxyxilane,di-t-butyldimethoxysilane, di-(2-methylcyclopentyl)dimethoxysilane,di-(3-methylcyclopentyl)dimethoxysilane,di-(2-ethylcyclopentyl)dimethoxysilane,di-(2,3-dimethylcyclopentyl)dimethoxysilane,di-(2,4-dimethylcyclopentyl)dimethoxysilane,di-(2,5-dimethylcyclopentyl)dimethoxysilane,di-(2,3-diethylcyclopentyl)dimethoxysilane,di-(2,3,4-trimethylcyclopentyl)dimethoxysilane,di-(2,3,5-trimethylcyclopentyl)dimethoxysilane,di-(2,3,4-triethylcyclopentyl)dimethoxysilane,di-(tetramethylcyclopentyl)dimethoxysilane,di-(tetraethylcyclopentyl)dimethoxysilane,di-(2-methylcyclopentenyl)dimethoxysilane,di-(3-methylcyclopentenyl)dimethoxysilane, di-(2-ethylcyclopentenyl)diethoxysilane, di-(2-n-butylcyclopentenyl)dimethoxysilane, di-(2,3-dimethylcyclopentenyl) dimethoxysilane,di-(2,4-dimethylcyclopentenyl)dimethoxysilane,di-(2,5-dimethylcyclopentenyl)dimethoxysilane,di-(2,3,4-trimethylcyclopentenyl)dimethoxysilane,di-(2,3,5-triethylcyclopentenyl)dimethoxysilane,di-(2,3,4-triethylcyclopentenyl)dimethoxysilane,di-(tetraethylcyclopentenyl) dimethoxysilane,di-(tetraethylcyclopentenyl)diethoxysilane,di-(2-methylcyclopentadienyl) dimethoxysilane,di-(3-methylcyclopentadienyl)dimethoxysilane,di-(2-ethylcyclopentadienyl)dimethoxysilane,di-(2-n-butylcyclopentadienyl)dimethoxysilane,di-(2,3-dimethylcyclopentadienyl)dimethoxysilane,di-(2,4-dimethylcyclopentadienyl)dimethoxysilane,di-(2,5-dimethylcyclopentadienyl)dimethoxysilane,di-(2,3-diethylcyclopentadienyl)dimethoxysilane,di-(2,3,4-trimethylcyclopentadienyl)dimethoxysilane,di-(2,3,5-trimethylcyclopentadienyl)dimethoxysilane,di-(2,3,4-triethylcyclopentadienyl)dimethoxysilane,di-(2,3,4,5-tetramethylcyclopentadienyl)dimethoxysilane,di-(2,3,4,5-tetraethylcyclopentadienyl)dimethoxysilane,di-(1,2,3,4,5-pentamethylcyclopentadienyl)dimethoxysilane,di-(1,2,3,4,5-pentaethylcyclopentadienyl)dimethoxysilane,di-t-amyl-dimethoxysilane, di-(α,α′-dimethylbenzyl)dimethoxysilane,di-(admantyl)dimethoxysilane, admantyl-t-butyldimethoxysilane,cyclopentyl-t-butyldimethoxysilane, di-isopropyldimethoxysilane,di-s-butyldimethoxysilane, di-s-amyldimethoxysilane, andisopropyl-s-butyldimethoxysilane.

[0253] When n is 3, the organosilicon compound represented by theformula (c-i) includes monoalkoxysilanes such astricyclopentylmethoxysilane, tricyclopentylethoxysilane,dicyclopentylmethylmethoxysilane, dicyclopentylethylmethoxysilane,dicyclopentylmethylethoxysilane, dicyclopentyldimethylmethoxysilane,cyclopentyldiethylmethoxysilane, and cyclopentyldimethylethoxysilane.

[0254] Of these, preferred are dimethoxysilanes, particularly preferredare dimethoxysilanes represented by the formula (c-ii), to beconcretely, preferably used is dicyclopentyldimethoxysilane,di-t-butyldimethoxysilane, di-(2-methylcyclopentyl)dimethoxysilane,di-(3-methylcyclopentyl)dimethoxysilane or do-t-amyldimethoxysilane.

(D) Polyether Compound

[0255] In the compound having at least two ether linkages spaced byplural atoms (hereinafter referred as “polyether compound”) used in thepresent invention, the atoms between these ether linkages are at leastone atom selected from the group consisting of carbon, silicon, oxygen,sulfur, phosphorus and boron, and the number of the atoms are not lessthan two. Of the polyether compounds, preferred are those in which arelatively bulky substituent attaches to the atom spacing the etherlinkages. The relatively bulky substituent has desirably a linear,branched or cyclic structure contaning 2 or more, preferably 3 or more,of carbon atoms. Particularly preferred are those having a branched orcyclic structure. Further, preferred is a polyether compound containinga plurality of, particularly 3 to 20, more particularly 3 to 10,especially 3 to 7 carbon atoms as the atoms spacing at least two etherlinkages.

[0256] The polyether compound as mentioned above can be represented, forexample, by the following formula:

[0257] wherein n is an integer satisfying the condition of 2≦n≦10; R¹ toR²⁶ are each a substituent having at least one atom selected from thegroup consisting of carbon, hydrogen, oxygen, halogen, nitrogen, sulfur,phosphorus, boron and silicon; any optional combination of from R¹ toR²⁶, preferably from R¹ to R², may form together a ring other than abenzene ring; and the main chain of the compound may contain atoms otherthan carbon.

[0258] The polyether compound as illustrated above includes2-(2-ethylhexyl)-1,3-dimethoxypropane, 2-isopropyl-1,3-dimethoxypropane,2-butyl-1,3-dimethoxypropane, 2-s-butyl-1,3-dimethoxypropane,2-cyclohexyl-1,3-dimethoxypropane, 2-phenyl-1,3-dimethoxypropane,2-cumyl-1,3-dimethoxypropane, 2-(2-phenylethyl)-1,3-dimethoxypropane,2-(2-cyclohexylethyl)-1,3-dimethoxypropane,2-(p-chlorophenyl)-1,3-dimethoxypropane,2-(diphenylmethyl)-1,3-dimethoxypropane,2-(1-naphthyl)-1,3-dimethoxypropane,2-(2-fluorophenyl)-1,3-dimethoxypropane,2-(1-decahydronaphthyl)-1,3-dimethoxypropane,2-(p-t-butylphenyl)-1,3-dimethoxypropane,2,2-dicyclohexyl-1,3-dimethoxypropane,2,2-dicyclopentyl-1,3-dimethoxypropane,2,2-diethyl-1,3-dimethoxypropane, 2,2-dipropyl-1,3-dimethoxypropane,2,2-diisopropyl-1,3-dimethoxypropane, 2,2-dibutyl-1,3-dimethoxypropane,2-methyl-2-propyl-1,3-dimethoxypropane,2-methyl-2-benzyl-1,3-dimethoxypropane,2-methyl-2-ethyl-1,3-dimethoxypropane,2-methyl-2-iso-propyl-1,3-dimethoxypropane,2-methyl-2-phenyl-1,3-dimethoxypropane,2-methyl-2-cyclohexyl-1,3-dimethoxypropane,2,2-bis(p-chlorophenyl)-1,3-dimethoxypropane,2,2-bis(2-cyclohexylethyl)-1,3-dimethoxypropane,2-methyl-2-iso-butyl-1,3-dimethoxypropane,2-methyl-2-(2-ethylhexyl)-1,3-dimethoxypropane,2,2-di-iso-butyl-1,3-dimethoxypropane,2,2-diphenyl-1,3-dimethoxypropane, 2,2-dibenzyl-1,3-dimethoxypropane,2,2-bis(cyclohexylmethyl)-1,3-dimethoxypropane,2,2-di-iso-butyl-1,3-diethoxypropane,2,2-di-iso-butyl-1,3-dibutoxypropane,2-iso-butyl-2-iso-propyl-1,3-dimethoxypropane,2-(1-methylbutyl)-2-isopropyl-1,3-dimethoxypropane,2-(1-methylbutyl)-2-s-butyl-1,3-dimethoxypropane,2,2-di-s-butyl-1,3-dimethoxypropane,2,2-di-t-butyl-1,3-dimethoxypropane,2,2-dineopentyl-1,3-dimethoxypropane,2-iso-propyl-2-iso-pentyl-1,3-dimethoxypropane,2-phenyl-2-isopropyl-1,3-dimethoxypropane,2-phenyl-2-s-butyl-1,3-dimethoxypropane,2-benzyl-2-isopropyl-1,3-dimethoxypropane,2-benzyl-2-s-butyl-1,3-dimethoxypropane,2-phenyl-2-benzyl-1,3-dimethoxypropane,2-cyclopentyl-2-isopropyl-1,3-dimethoxypropane,2-cyclopentyl-2-s-butyl-1,3-dimethoxypropane,2-cyclohexyl-2-isopropyl-1,3-dimethoxypropane,2-cyclohexyl-2-s-butyl-1,3-dimethoxypropane,2-isopropyl-2-s-butyl-1,3-dimethoxypropane,2-cyclohexyl-2-cyclohexylmethyl-1,3-dimethoxypropane,2,3-diphenyl-1,4-diethoxybutane, 2,3-dicyclohexyl-1,4-diethoxybutane,2,2-dibenzyl-1,4-diethoxybutane, 2,3-dicyclohexyl-1,4-diethoxybutane,2,3-di-iso-propyl-1,4-diethoxybutane,2,2-bis(p-methylphenyl)-1,4-dimethoxybutane,2,3-bis(p-chlorophenyl)-1,4-dimethoxybutane,2,3-bis(p-fluorophenyl)-1,4-dimethoxybutane,2,4-diphenyl-1,5-dimethoxypentane, 2,5-diphenyl-1,5-dimethoxyhexane,2,4-di-iso-propyl-1,5-dimethoxypentane,2,4-di-iso-butyl-1,5-dimethoxypentane,2,4-di-iso-amyl-1,5-dimethoxypentane, 3-methoxymethyltetrahydrofuran,3-methoxymethyldioxane, 1,3-di-iso-butoxypropane,1,2-di-iso-butoxypropane, 1,2-di-iso-butoxyethane,1,3-di-iso-amyloxypropane, 1,3-di-iso-neopentyloxyethane,1,3-dineopentyloxypropane, 2,2-tetramethylene-1,3-dimethoxypropane,2,2-pentamethylene-1,3-dimethoxypropane,2,2-hexamethylene-1,3-dimethoxypropane,1,2-bis(methoxymethyl)cyclohexane, 2,8-dioxaspiro[5,5]undecane,3,7-dioxabicyclo[3,3,1]nonane, 3,7-dioxabicyclo[3,3,0]octane,3,3-di-iso-butyl-1,5-oxononane, 6,6-di-iso-butyldioxyheptane,1,1-dimethoxymethylcyclopentane, 1,1-bis(dimethoxymethyl)cyclohexane,1,1-bis(methoxymethyly)bicyclo[2,2,1]heptane,1,1-dimethoxymethylcyclopentane,2-methyl-2-methoxymethyl-1,3-dimethoxypropane,2-cyclohexyl-2-ethoxymethyl-1,3-diethoxypropane,2-cyclohexyl-2-methoxymethyl-1,3-dimethoxypropane,2,2-di-iso-butyl-1,3-dimethoxycyclohexane,2-iso-propyl-2-iso-amyl-1,3-dimethoxycyclohexane,2-cyclohexyl-2-methoxymethyl-1,3-dimethoxycyclohexane,2-iso-propyl-2-methoxymethyl-1,3-dimethoxycyclohexane,2-iso-butyl-2-methoxymethyl-1,3-dimethoxycyclohexane,2-cyclohexyl-2-ethoxymethy-1,3-diethoxycyclohexane,2-cyclohexyl-2-ethoxymethyl-1,3-dimethoxycyclohexane,2-iso-propyl-2-ethoxymethyl-1,3-diethoxycyclohexane,2-iso-propyl-2-ethoxymethyl-1,3-diethoxycyclohexane,2,-iso-buty-2-ethoxymethyl-1,3-diethoxycyclohexane,2-iso-butyl-2-ethoxymethyl-1,3-dimethoxycyclohexane, tris(p-methoxyphenyl)phospine, methlphenylbis (methoxymethyl) silane,diphenylbis (methoxymethyl)silane,methylcyclohexylbis(methoxymethyl)silane,di-t-butylbis(methoxymethyl)silane,cyclohexyl-t-butylbis(methoxymethyl)silane andiso-propyl-t-butylbis(methoxymethyl)silane.

[0259] Of these compounds, preferred are 1,3-diethers, espesially,2,2-di-iso-butyl-1,3-dimethoxypropane,2-iso-propyl-2-iso-pentyl-1,3-dimethoxypropane, 2,2-dicyclohexyl-1,3dimethoxypropane, 2-cyclohexyl-2-isopropyl-1,3-dimethoxypropane,2-isopropyl-e-s-butyl-1,3-dimethoxypropane,2,2-diphenyl-1,3-dimethoxypropane,2-cyclopentyl-2-isopropyl-1,3-dimethoxypropane and2,2-bis(cyclohexylmethyl)1,3-dimethoxypropane. These compounds may beused either singly or in combination.

[III] Organometallic Compound Catalyst Component

[0260] In the present invention, the same component as the aforesaidorganometallic compound catalyst component (B) can be used as theorganometallic compound catalyst component [III].

[0261] The type of the organometallic compound catalyst component [III ]may be the same as or different from that of the organometallic compoundcatalyst component (B) used in the preparation of the contact product[I-1 or the prepolymerized catalyst [Ia-1]. However, the catalyst (1) or(1 a) can be formed with or without the organometallic compound catalystcomponent [III], i.e., the catalyst component [III] can be usedoptionally.

[0262] With regard to whether or not the organometallic compoundcatalyst component [III] is used for forming the catalysts (2), (2 a),(3), (3 a), (4), (4 a) and (5 a) which are described later, the abovestatement is also applied to.

Olefin Polymerization Catalysts (1) and (1 a)

[0263] The olefin polymerization catalyst (1) according to the inventionis formed from:

[0264] [I-1] the contact product obtained by contacting:

[0265] (A) the solid titanium catalyst component,

[0266] (B) the organometallic compound catalyst component, andoptionally,

[0267] (C) the organosilicon compound represented by the formula (c-i);

[0268] (D) the polyether compound; and optionally,

[0269] [II-1]

[0270] [III] the organometallic compound catalyst component, asdescribed above.

[0271] The olefin polymerization catalyst (1 a) according to theinvention is formed from:

[0272] [Ia-1] a prepolymerized catalyst component obtained byprepolymerizing an olefin of 2 or more carbon atoms in the presence ofthe catalyst components for forming the contact product [I-1] in such away that the amount of the prepolymer formed is 0.01 to 2,000 g based on1 g of the solid titanium catalyst component (A);

[0273] [II-1] (D) the polyether compound; and optionally,

[0274] [III] the organometallic compound catalyst component, asdescribed above.

[0275] When the contact product [I-1] is prepared by contacting thesolid titanium catalyst component (A), the organometallic compoundcatalyst component (B) and the specific organosilicon compound (C), theorganometallic compound catalyst component (B) is used in an amount ofusually 0.1 to 100 mmol, preferably 0.5 to 50 mmol, based on 1 mol oftitanium atom contained in the solid titanium catalyst component (A),and the organosilicon compound (C) is used in an amount of usually 0.1to 50 mol, preferably 0.5 to 30 mol, more preferably 1 to 10 mol, basedon 1 mol of the titanium atom.

[0276] There is no limitation on the order of contacting thesecomponents (A), (B) and (C).

[0277] In the present invention, preferred is the prepolymerizedcatalyst [Ia-1] obtained by prepolymerizing an olefin or 2 or morecarbon atoms in the presense of the contact product [I-1] of thecatalyst components (A), (B) and (C).

[0278] Examples of the olefins of 2 or more carbon atoms which can beprepolymerized include:

[0279] linear α-olefins, such as ethylene, propylene, 1-butene,1-pentene, 1-hexene, 1-octene, 1-decene, 1-dodecene, 1-tetradecene,1-hexadecene, 1-octadecene and 1-eicosene;

[0280] cycloolefins, such as cyclopentene, cycloheptene, norbornene,5-ethyl-2-norbornene, tetracyclododecene,2-ethyl-1,4,5,8-dimethano-1,2,3,4,4a,5,8,8a-octahydronaphthalene; and

[0281] olefins represented by the following formulas (i) and (ii):

H₂C═CH—X  (i)

H₂C═CH—CH₂x  (ii)

[0282] wherein X is a cycloalkyl group, an aryl group or

[0283] M is carbon or silicon, R¹ and R² are each a hydrocarbon group,and R³ is hydrogen or a hydrocarbon group.

[0284] Examples of the cycloalkyl group X in the formula (i) includecyclopentyl, cyclohexyl and cycloheptyl. Examples of the aryl group Xinclude phenyl, tolyl, xylyl and naphthyl.

[0285] Examples of the hydrocarbon groups indicated by R¹, R² and R³include an alkyl group such as methyl, ethyl, propyl and butyl; an arylgroup such as phenyl and naphthyl; and a norbornyl group. Thehydrocarbon groups R¹, R² and R³ may contain silicon and halogen,respectively.

[0286] Examples of the olefins represented by the formulae (i) and (ii)include 3-methyl-1-butene, 3-methyl-1-pentene, 3-ethyl-1-pentene,4-methyl-1-pentene, 4-methyl-1-hexene, 4,4-dimethyl-1-hexene,4,4-dimethyl-1-pentene, 4-ethyl-1-hexene, 3-ethyl-1-hexene,allylnaphthalene, allylnorbornane, styrene, dimethylstyrenes,vinylnaphthalenes, allyltoluenes, allylbenzene, vinylcyclohexane,vinylcyclopentane, vinylcycloheptane and allytrialkylsilanes.

[0287] Of these, preferred are 3-methyl-1-butene, 3-methyl-1-pentene,3-ethyl-1-hexene, vinylcyclohexane, allyltrimethylsilane,dimethylstyrene and propylene; more preferred are 3-methyl-1-butene,vinylcyclohexane and allyltrimethylsilane; and particularly preferred is3-methyl-1-butene.

[0288] These olefins may be used in combination of two or more kinds.

[0289] The prepolymerized catalyst [Ia-1] for use in the invention isobtained by prepolymerizing the above-mentioned olefin in such a waythat the amount of the prepolymer is 0.01 to 2,000 g, preferably 0.1 to200 g, based on 1 g of the solid titanium catalyst component (A).

[0290] It is desired that a concentration of the solid titanium catalystcomponent (A) during the prepolymerization is in the range of usuallyabout 0.01 to 200 mmol, preferably about 0.05 to 100 mmol, in terms oftitanium atom, based on 1 liter of the polymerization volume.

[0291] In the preparation of the prepolymerized catalyst [Ia-1], theorganometallic compound catalyst component (B) and the organosiliconcompound (C) may be used in the same amounts as used for preparing theaforesaid contact product [I-1].

[0292] The prepolymerization can be carried out, for example, by addingthe olefin to the catalyst components in the presence of apolymerization-inactive hydrocarbon medium to react them under mildconditions.

[0293] Examples of the inert hydrocarbon solvents used herein includealiphatic hydrocarbons such as propane, butane, pentane, hexane,heptane, octane, decane, dodecane and kerosine; alicyclic hydrocarbonssuch as cyclopentane, cyclohexane and methylcyclopentane; aromatichydrocarbons such as benzene, toluene and xylene; halogenatedhydrocarbons such as ethylene chloride and chlorobenzene; and mixturesof these hydrocarbons. Of these inert hydrocarbon solvents, particularlypreferred are aliphatic hydrocarbons.

[0294] There is no limitation on the reaction temperature for theprepolymerization, so far as the resulting prepolymer is notsubstantially dissolved in the inert hydrocarbon solvent. In general,the temperature is in the range of about −20 to +100° C., preferablyabout −20 to +80° C., more preferably 0 to +40° C.

[0295] A molecular weight regulator such as hydrogen may be used in theprepolymerization.

[0296] The prepolymerization may be carried out either batchwise,semi-continuously or continuously.

[0297] In the preparation of the contact product [I-1] and theprepolymerized catalyst [Ia-1], other compounds useful for the catalystformation may be used together with the above-mentioned components. Forexample, an electron donor (b) may be used together with theorganosilicon compound (C).

[0298] Employable as the electron donor (b) are the electron donor (a)which is used for preparing the solid titanium catalyst component (A)and the following nitrogen-containing compounds, oxygen-containingcompounds and phosphorus-containing compounds.

[0299] Examples of the nitrogen-containing compounds employable as theelectron donor (b) include 2,6-substituted piperidines, 2,5-substitutedpiperidines, and substituted methylenediamines such asN,N,N′,N′-tetramethylmethylenediamine,N,N,N′,N′-tetraethylmethylenediamine, 1,3-dibenzylimidazoline and1,3-dibenzyl-2-phenylimidazoline.

[0300] Examples of the phosphorus-containing compounds employable as theelectron donor (b) include phosphites such as triethyl phosphite,tri-n-propyl phosphite, triisopropyl phosphite, tri-n-butyl phosphite,triisobutyl phosphite, diethyl-n-butyl phosphite and diethylphenylphosphite.

[0301] Examples of the oxygen-containing compounds employable as theelectron donor (b) include 2,6-substituted tetrahydropyrans and2,5-substituted tetrahydropyrans.

[0302] Furthermore, an organosilicon compound (E) represented by thefollowing formula (c-iii) may be used;

R_(n)Si(OR″)_(4−n)  (c-iii)

[0303] wherein each of R and R′ is a hydrocarbon group, and n is anumber satisfying the condition of 0<n<4.

[0304] Specific examples of the organosilicon compounds represented bythe above formula (c-iii) include:

[0305] trimethylmethoxysilane, trimethylethoxysilane,dimethyldimethoxysilane, dimethyldiechoxysilane,diisopropyldimethoxysilane, diphenyldimethoxysilane,phenylmethyldimethoxysilane, diphenyldiethoxysilane,bis-o-tolyldimethoxysilane, bis-m-tolyldimethoxysilane,bis-p-tolyldimethoxysilane, bis-p-tolyldiethoxysilane,bis-ethylphenyldimethoxysilane, ethyltrimethoxysilane,ethyltriethoxysilane, vinyltrimethoxysilane, methyltrimethoxysilane,n-propyltriethoxysilane, decyltrimethoxysilane, decyltriethoxysilane,phenyltrimethoxysilane, γ-chloropropyltrimethoxysilane,methyltriethoxysilane, ethyltriethoxysilane, vinyltriethoxysilane,n-butyltriethoxysilane, phenyltriethoxysilane,γ-aminopropyltriethoxysilane, chlorotriethoxysilane,ethyltriisopropoxysilane, vinyltributoxysilane, ethyl silicate, butylsilicate, trimethylphenoxysilane, methyltriallyoxysilane,vinyltris(β-methoxyethoxysilane), vinyltriacetoxysilane anddimethyltetraethoxysiloxane.

[0306] The organosilicon compound (E) represented by the formula (c-iii)may be the same as the organosilicon compound (C) represented by theformula (c-i).

[0307] When preparing the olefin polymerization catalyst (1) (or (1 a))formed from:

[0308] [I-1] the contact product (or [Ia-1] the prepolymerizedcatalyst),

[0309] [II-1] the electron donor composed of the polyether compound (D),and optionally,

[0310] [III] the organometallic compound catalyst component,

[0311] the polyether compound (D) as the electron donor [II-1] is usedin an amount of 0.001 to 5,000 mol, preferably 0.01 to 1,000 mol, basedon 1 mol of titanium atom contained in the contact product [I-1] or theprepolymerized catalyst [Ia-1].

[0312] The organometallic compound catalyst component [III] is used,optionally, in an amount of 1 to 2,000 mol, preferably 2 to 1,000 mol,based on 1 mol of the titanium atom.

[0313] When the olefin polymerization catalyst is formed from thecontact product [I-1] (or the prepolymerized catalyst [Ia-1], thepolyether compound (D) (electron donor [II-1]) and the organometalliccompound catalyst component [III], other compounds useful for thecatalyst formation, e.g., the aforesaid electron donors (a) and (b), canbe used if desired.

[0314] By the use of the olefin polymerization catalyst (1) (or (1 a))of the invention which is formed from the contact product [I-1] (or theprepolymerized catalyst [Ia-1]) comprising the specific catalystcomponents and the electron donor composed of the specific polyethercompound (D), there can be prepared a polypropylene having a higherisotacticity and a propylene block copolymer comprising a polypropylenecomponent having a higher isotacticity and a rubber component having ahigher molecular weight, as compared with those obtained usingconventionally known olefin polymerization catalysts.

Olefin Polymerization Catalysts (2) and (2 a)

[0315] The olefin polymerization catalyst according to the invention isformed from:

[0316] [I-2] the contact product obtained by contacting:

[0317] (A) the solid titanium catalyst component,

[0318] (B) the organometallic compound catalyst component, and

[0319] (D) the polyether compound;

[0320] (C) the organosilicon compound represented by the formula (c-i);and optionally,

[0321] [II-2]

[0322] [III] the organometallic compound catalyst component, asdescribed above.

[0323] The olefin polymerization catalyst (2 a) according to theinvention is formed from:

[0324] [Ia-2] the prepolymerized catalyst obtained by prepolymerizing anolefin of 2 or more carbon atoms in the presence of the catalystcomponents for forming the contact product [I-1] in such a way that theamount of the prepolymer formed is 0.01 to 2,000 g based on 1 g of thesolid titanium catalyst component (A);

[0325] [II-2] (C) the organosilicon compound represented by the formula(c-i); and optionally,

[0326] [III] the organometallic compound catalyst component, asdescribed above.

[0327] When the contact product [I-2] is prepared by contacting thesolid titanium catalyst component (A), the organometallic compoundcatalyst component (B) and the polyether compound (D), theorganometallic compound catalyst component (B) is used in an amount ofusually 0.1 to 100 mmol, preferably 0.5 to 50 mmol, based on 1 mol oftitanium atom contained in the solid titanium catalyst component (A),and the polyether compound (D) is used in an amount of usually 0.1 to 50mol, preferably 0.5 to 30 mol, more preferably 1 to 10 mol, based on 1mol of the titanium atom.

[0328] There is no limitation on the order of contacting thesecomponents (A), (B) and (D).

[0329] The prepolymerized catalyst [1a-2] is prepared in the same manneras for the preparation of the prepolymerized catalyst [Ia-1] except thatthe polyether compound (D) is used in place of the organosiliconcompound (C).

[0330] The same α-olefins of 2 or more carbon atoms as used forpreparing the prepolymerized catalyst [1a-1] can be used for preparingthe prepolymerized catalyst [1a-2]. Among those α-olefins, preferred arepropylene, 1-butene, 1-pentene, 3-methyl-1-butene, 3-methyl-1-pentene,3-ethyl-1-hexene, vinylcyclohexane, allyltrimethylsilane anddimethylstyrene, and of these, more preferred are propylene,3-methyl-1-butene and vinylcyclohexane, allyltrimethylsilane. Theseα-olefins may be used in combination of two or more kinds.

[0331] This prepolymerization is desirably carried out in such a waythat the amount of the prepolymer formed is 0.01 to 2,000 g, preferably0.1 to 200 g, based on 1 g of the solid titanium catalyst component (A).

[0332] When the olefin polymerization catalyst (2) (or (2 a)) isprepared from the contact product [I-2] (or prepolymerized catalyst[Ia-2]), the organosilicon compound (C) represented by the formula (c-i)(electron donor [II-2]) and, optionally, the organometallic compoundcatalyst component [III], the organosilicon compound (C) (electron donor[II-2]) is used in an amount of usually 0.001 to 5,000 mol, preferably0.01 to 1,000 mol, based on 1 mol of titanium atom contained in thecontact product [I-2] or the prepolymerized catalyst [Ia-2].

[0333] The organometallic compound catalyst component [III] is used,optionally, in an amount of 1 to 2,000 mol, 58 preferably 2 to 1,000mol, based on 1 mol of the titanium atom.

[0334] When the olefin polymerization catalyst is prepared from thecontact product [I-2] (or prepolymerized catalyst [Ia-2]), the specificorganosilicon compound (C) (electron donor [II-2]) and theorganometallic compound catalyst component [III], other componentsuseful for the catalyst formation may be used in combination with thesecomponents. For example, the aforesaid electron donors (a) and (b) canbe used if desired.

[0335] By the use of the olefin polymerization catalyst (2) (or (2 a))of the invention which is formed from the contact product [I-2] (or theprepolymerized catalyst [Ia-2]) comprising the specific catalystcomponents and the specific organosilicon compound (C), there can beprepared a polypropylene having a higher isotacticity and a propyleneblock copolymer comprising a polypropylene component having a higherisotacticity and a rubber component having a higher molecular weight ascompared with those obtained using conventionally known olefinpolymerization catalysts.

Process for Preparing Homopolypropylene

[0336] In the first process for preparing homopolypropylene according tothe invention, propylene is polymerized in the presence of the olefinpolymerization catalyst (1) or (1 a) to prepare homopolypropylene.

[0337] In the present invention, it is preferred to polymerize onlypropylene to prepare of homopolypropylene, but propylene may becopolymerized with a small amount of other α-olefin than propylene, withthe proviso that the objects of the invention are not marred.

[0338] Examples of the other α-olefins copolymerizable with propyleneinclude ethylene and α-olefins of 4 to 20 carbon atoms such as 1-butene,1-pentene, 1-hexene, 1-octene, 1-decene, 1-dodecene, 1-tetradecene,1-hexadecene, 1-octadecene, 1-eicosene, 3-methyl-1-butene,3-methyl-1-pentene, 3-ethyl-1-pentene, 4-methyl-1-pentene,4-methyl-1-hexene, 4,4-dimethyl-1-hexene, 4,4-dimethyl-1-pentene,4-ethyl-1-hexene and 3-ethyl-1-hexene.

[0339] Also employable are other olefins than α-olefins, such as thoseused for the prepolymerization, and diene compounds described later forpreparing an ethylene/α-olefin copolymer component of the propyleneblock copolymer.

[0340] The olefin other than propylene is used in such an amount thatthe units derived therefrom are finally present in an amount of not morethan 5% by mol, preferably not more than 4% by mol, in the resultingpolypropylene.

[0341] In the present invention, the polymerization of propylene can becarried out in two or more steps under different reaction conditions.

[0342] The polymerization may be performed by a solvent suspensionpolymerization process, a suspension polymerization process using liquidpropylene as a solvent, a gas phase polymerization process or the like.

[0343] In the solvent suspension polymerization process, a hydrocarbonwhich is polymerization-inactive can be used as a polymerizationsolvent. For example, hydrocarbons described with respect to theprepolymerization, particularly aliphatic hydrocarbons, can be employed.

[0344] In the polymerization system, the contact product [I-1] or theprepolymerized catalyst component [Ia-1] is used in an amount of usuallyabout 0.0001 to 50 mmol, preferably about 0.001 to 10 mmol, in terms oftitanium atom, based on 1 liter of the polymerization volume.

[0345] The electron donor [II-1] (polyether compound (D)) is used in anamount of usually 0.001 to 5,000 mol, preferably 0.01 to 1,000 mol,based on 1 mol of the titanium atom. The organometallic compoundcatalyst component [III] is used, optionally, in an amount of usually 1to 2,000 mol, preferably 2 to 1,000 mol, based on 1 mol of the titaniumatom in the polymerization system.

[0346] The polymerization of propylene is performed at a temperature ofusually about −50 to 200° C., preferably about 50 to 100° C., and apressure of usually atmospheric pressure to 100 kg/cm², preferably about2 to 50 kg/cm.

[0347] The polymerization of propylene can be carried out eitherbatchwise, semi-continuously or continuously.

[0348] In the polymerization of propylene, hydrogen (chain transferagent) may be used to regulate a molecular weight of the resultingpolypropylene. In this invention, it is desired to use hydrogen in anamount of not more than 0.5 mol, preferably not more than 0.4 mol, morepreferably not more than 0.3 mol, based on 1 mol of propylene, althoughthe amount varies depending on the molecular weight of the resultingpolymer.

[0349] In the process for preparing homopolypropylene using the olefinpolymerization catalyst (1) or (1 a) according to the invention,homopolypropylene having a high melt flow rate and a high isotacticitycan be prepared by the use of a small amount of hydrogen.

[0350] In the case where the aforesaid prepolymerized catalyst [Ia-1] isused in the process of the invention to prepare homopolypropylene, it isdesired that the prepolymer formed by the prepolymerization is containedin the finally obtained homopolypropylene in an amount of 0.001 to 3% byweight, preferably 0.005 to 2% by weight.

[0351] In the second process for preparing homopolypropylene accordingto the invention, propylene is polymerized in the presence of the olefinpolymerization catalyst (2) or (2 a) to prepare homopolypropylene.

[0352] The second process for preparing homopolypropylene can be carriedout in the same manner as that of the first process for preparinghomopolypropylene except that the olefin polymerization catalyst (2) or(2 a) is used.

[0353] In the polymerization system of the second process for preparinghomopolypropylene, the contact product [I-2] or the prepolymerizedcatalyst component [Ia-2] is used in an amount of usually about 0.0001to 50 mmol, preferably about 0.001 to 10 mmol, in terms of titaniumatom, based on 1 liter of the polymerization volume.

[0354] The electron donor [II-2] (organosilicon compound (C)) is used inan amount of usually 0.001 to 5000 mol, preferably 0.01 to 1000 mol,based on 1 mol of the titanium atom. The organometallic compoundcatalyst component [III] is used, optionally, in an amount of usually 1to 2,000 mol, preferably 2 to 1,000 mol, based on 1 mol of the titaniumatom in the polymerization system.

[0355] In this invention, an yield of the homopolypropylene per unitamount of the solid titanium catalyst component (A) is high, so that theamount of the catalyst residue (particularly halogen content) in theresulting homopolypropylene can be relatively reduced. Accordingly, anoperation for removing the catalyst residue contained in the product canbe omitted, and moreover, a mold can be effectively prevented fromoccurrence of rust in the molding process of homopolypropylene.

Homopolypropylene

[0356] According to the processes of the invention, highly isotactichomopolypropylene can be obtained as described above.

[0357] Properties of the homopolypropylene obtained by the invention anda propylene block copolymer described later (hereinafter sometimescalled generically “propylene polymer”) are described with reference totheir boiling heptane-insoluble component (i) and 23° C.n-decane-soluble component (ii). The boiling heptane-insoluble component(i) is mainly a crystalline portion of the propylene polymer, and the23° C. n-decane-soluble component (ii) is mainly a non-crystalline orlow-crystalline portion of the propylene polymer.

[0358] The amount of the boiling heptane-insoluble component (i) of thepropylene polymer greatly depends on the amount of the 23° C.n-decane-soluble component (ii). The boiling heptane-insoluble component(i) is contained in a n-decane-insoluble component, that is a residue ofthe 23° C. n-decane-soluble component (ii), in an amount of usually notless than 80% by weight, preferably not less than 85% by weight, morepreferably not less than 90% by weight, still more preferably not lessthan 93% by weight, particularly preferably not less than 94% by weight,though the amount thereof cannot be defined in general. The amount ofthe boiling heptane-insoluble component (i) is calculated on theassumption that the 23° C. n-decane-soluble component (ii) is solublealso in boiling heptane.

[0359] The boiling heptane-insoluble component (i) of the propylenepolymer can be obtained in the following manner.

[0360] A 1-liter flask equipped with a stirrer is charged with 3 g of apolymer sample, 20 mg of 2,6-di-tert-butyl-4-methylphenol and 500 ml ofn-decane, and heated at 145° C. in an oil bath to dissolve the polymersample. After the polymer sample is dissolved, the resulting solution iscooled to room temperature over a period of about 8 hours, followed bykeeping it for 8 hours in a water bath of 23° C. so as to precipitate apolymer. The resulting n-decane suspension containing the precipitatedpolymer (23° C. n-decane-insoluble component) is separated by filtrationthrough a glass filter of G-4 (or G-2) and dried under reduced pressure.Then, 1.5 g of the polymer thus dried is extracted with heptane bySoxhlet extractor over a period of not shorter than 6 hours. Thus, aboiling heptane-insoluble component (i) is obtained as the extractionresidue.

[0361] The homopolypropylene obtained by the invention contains such aboiling heptane-insoluble component (i) as mentioned above in an amountof not less than 80% by weight, preferably not less than 90% by weight,more preferably not less than 93% by weight, particularly preferably notless than 95% by weight.

[0362] This boiling heptane-insoluble component (i) essentially consistsof units derived from propylene, but in some cases it contains a part ofunits derived from other olefins than propylene which are used in thepreparation of homopolypropylene. The boiling heptane-insolublecomponent (i) of the homopolypropylene may contain the units derivedfrom other olefin than propylene in an amount of not more than 5 % bymol, preferably not more than 4% by mol.

[0363] As described above, the crystalline portion of thehomopolypropylene (propylene polymer) is evaluated by its boilingheptane-insoluble component (i), in other words, the crystalline portioncan be evaluated by a pentad isotacticity [M_(g)] and a pentad tacticity[M₃] of the boiling heptane-insoluble component (i), details of whichare described below.

[0364] (i-1) The boiling heptane-insoluble component (i) of thehomopolypropylene obtained by the invention desirably has a pentadisotacticity [M_(g)] of not less than 0.97, preferably 0.970 to 0.995,more preferably 0.980 to 0.995, particularly preferably 0.982 to 0.995.

[0365] A value of the pentad isotacticity [M_(g)] of the boilingheptane-insoluble component (i) can be determined by the ¹³C-NMRspectrum and the following formula (1). $\begin{matrix}{\left\lbrack M_{5} \right\rbrack = \frac{\lbrack{Pmmmm}\rbrack}{\lbrack{Pw}\rbrack - {2\left( {\left\lbrack {S\quad {\alpha\gamma}} \right\rbrack + \left\lbrack {S\quad {\alpha\delta}^{+}} \right\rbrack} \right)} + {3\left\lbrack {T\quad \delta^{+}\delta^{+}} \right\rbrack}}} & (1)\end{matrix}$

[0366] wherein

[0367] [Pmmmm] is absorption intensity of methyl groups on a thirdpropylene units in five propylene unit sequences where the five unitsare bonded isotactically to each other,

[0368] [Pw] is absorption intensity of all methyl groups in propyleneunits,

[0369] [Sαγ] is absorption intensity of secondary carbons in a mainchain, with the proviso that one of two tertiary carbons nearest to eachof said secondary carbons is situated at the α position and the other issituated at the γ position,

[0370] [Sαδ⁺] is absorption intensity of secondary carbons in a mainchain, with the proviso that one of two tertiary carbons nearest to eachof said secondary carbons is situated at the α position and the other issituated at the δ or father position, and

[0371] [Tδ⁺δ⁺] is absorption intensity of tertiary carbons in a mainchain, with the proviso that one of two tertiary carbons nearest to eachof said tertiary carbons is situated at the δ or farther position andthe other is also situated at the δ or farther position;

[0372] a pentad tacticity [M₃] of the boiling heptane-insolublecomponent determined by the following formula (2) using a ¹³C-NMRspectrum is in the range of 0.0020 to 0.0050:

[0373] Details of the pentad isotacticity [M_(g)] are described below.

[0374] When the boiling heptane-insoluble component (i) of the propylenepolymer consists of only the propylene polymer units, it can berepresented by the following structural formula (A).

[0375] If a propylene unit

[0376] is symbolized by ┘ or ┐, ┘ ┘ is expressed by “m” (meso form), and┘ ┐ is expressed by “r” (racemo form), five propylene isotactic unitsequences are expressed by ⁵⁴⁰ m ^(┘)m ^(┘)m ^(┘)m ^(┘). When absorptionintensity, in a ¹³C-NMR spectrum, of methyl groups (e.g., Me³, Me⁴) onthe third unit in the five propylene unit sequences where the five unitsare bonded isotacticaly to each other is expressed by [Pmmmm], andabsorption intensity of the whole methyl groups (e.g., Me¹, Me², Me³ . .. ) in the propylene units is expressed by [Pw], the stereoregularity ofthe boiling heptane-insoluble component (propylene polymer) representedby the above formula (A) can be evaluated by a value of the pentadisotacticity [M_(g)] obtained from the following formula (1A):$\begin{matrix}{\left\lbrack M_{5^{\prime}} \right\rbrack = \frac{\lbrack{Pmmmm}\rbrack}{\lbrack{Pw}\rbrack}} & \text{(1A)}\end{matrix}$

[0377] wherein [Pmmmm] and [Pw] have the meanings defined above.

[0378] Further, when the boiling heptane-insoluble component containsconstituent units derived from other olefins than propylene, forexample, ethylene units, in a small amount, said insoluble component canbe expressed by the following formula (B-1) or (B-2). The formula (B-1)shows that one ethylene unit is contained in a propylene unit sequence,and the formula (B-2) shows that an ethylene unit chain composed of twoor more ethylene units is contained in a propylene unit sequence.

[0379] (n is 0 or a positive integer)

[0380] In the above cases, for measurement of the pentad isotacticity,the absorption intensity of other methyl groups (Me⁴, Me⁵, Me⁶ and Me⁷in the formulas (B-1) and (B-2), respectively) than the methyl group onthe third unit in the five isotactic propylene unit sequence should betheoretically excluded. However, absorption of these methyl groups areobserved to be overlapped on absorption of other methyl groups, andhence it is difficult to quantitatively determine the absorptionintensity of those methyl groups.

[0381] On that account, when the streoregularity of the boilingheptane-insoluble component represented by the formula (B-1) isevaluated, absorption intensity (Sαγ), in the ¹³C-NMR spectrum, of asecondary carbon (C¹) which is in the ethylene unit and bonded to atertiary carbon (C^(a)) in the propylene unit and absorption intensity(Sαγ) of a secondary carbon (C³) which is in the propylene unit andbonded to the secondary carbon (C²) in the ethylene unit are excluded.

[0382] In other words, the absorption intensity of other methyl groups(Me⁴, Me⁵, Me⁶ and Me⁷) than the methyl groups on the third propyleneunits in the five isotactic propylene unit sequences are excluded bysubtracting, from Pw, a value of two times of absorption intensity (Sαγ)of a secondary carbon (C¹ or C³) in the main chain wherein out of twotertiary carbons nearest to said secondary carbon, one (C^(a) or C^(b))is situated at the a position and the other (C^(b) or C^(a)) is situatedat the y position.

[0383] When the stereoregularity of the boiling heptane-insolublecomponent represented by the formula (B-2) is evaluated, absorptionintensity (Sαδ³), in the ¹³C-NMR spectrum, of a secondary carbon (C⁴)which is in the ethylene unit chain composed of two or more ethyleneunits and bonded to a tertiary carbon (C_(d)) in the propylene unit andabsorption intensity (Sαδ⁺) of a secondary carbon (C⁶) which is in thepropylene unit and bonded to a secondary carbon (C⁵) in the ethyleneunit chain composed of two or more ethylene units are excluded.

[0384] In other words, the absorption intensity of other methyl groups(Me⁴, Me⁵, Me⁶ and Me⁷) than the methyl groups in the third propyleneunit in the five isotactic propylene unit sequences are excluded bysubtracting, from Pw, two times value of the absorption intensity [Sαδ⁺]of a secondary carbon (C⁴ or C⁶) in the main chain wherein out of twotertiary carbons nearest to said secondary carbon, one (C^(d) or C^(e))is situated at the α position and the other (C^(e) or C^(d)) is situatedat the δ or farther position.

[0385] Accordingly, the stereoregularity of the boilingheptane-insoluble component represented by the above formula (B-1) or(B-2) can be evaluated by a value [M_(5′′)] obtained from the followingformula (1B). $\begin{matrix}{\left\lbrack M_{5^{''}} \right\rbrack = \frac{\lbrack{Pmmmm}\rbrack}{\lbrack{Pw}\rbrack - {2\left( {\left\lbrack {S\quad {\alpha\gamma}} \right\rbrack + \left\lbrack {S\quad \alpha \quad \delta^{+}} \right\rbrack} \right)}}} & \text{(1B)}\end{matrix}$

[0386] When the boiling heptane-insoluble component contains a smallamount of ethylene units and the ethylene unit chain contains onepropylene unit, this insoluble component can be represented by thefollowing formula (C).

[0387] If the formula (lB) is applied to evaluation of thestereoregularity of the boiling heptane-insoluble component representedby the formula (C), a further correction should be made. The reason isthat there are four methyl groups corresponding to Sαγ or Sαδ⁺ in spitethat the number of the methyl groups to be excluded is five (Me⁴, Me⁵,Me⁶, Me⁷ and Me⁸), and if the formula (1B) is applied, the number of theexcluded methyl groups is larger by three than the number of methylgroups other than those on the third propylene units in the fivepropylene unit sequences.

[0388] Accordingly, a further correction is made by using absorptionintensity, in the ¹³C-NMR spectrum, of a tertiary carbon in thepropylene unit contained in the ethylene unit chain. In other words, thecorrection is made by adding, to Pw, a value of three times ofabsorption intensity [Tδ⁺δ⁺] of a tertiary carbon (C⁷) in the main chainwherein out of two tertiary carbons (C^(f), C^(g)) nearest to saidtertiary carbon, one (C^(f)) is situated at the δ or farther positionand the other (C^(g)) is also situated at the δ or farther position.

[0389] Thus, the stereoregularity of the boiled heptane-insolublecomponent can be evaluated by a value of the pentad isotacticity [M_(g)]obtained from the above formula (1).

[0390] Accordingly, the stereoregularity of the boiled heptane-insolublecomponent in the propylene block copolymer of the invention can beevaluated by a value of the pentad isotacticity [M_(g)] obtained fromthe following formula (1A).

[0391] The formula (1A) and the formula (1B) are included in the formula(1A), and they can be said to be special cases of the formula (1A).Further, if the boiling heptane-insoluble component contains units otherthan prpylene units, the correction as mentioned obove may beunnecessary depending on the kind of the other units.

[0392] (i-2) The boiling heptan-insoluble component of thehomopolypropylene obtained by the invention desirably has a pentadtacticity [M³] obtained from the following formula (2) using absorptionintensity in a ¹³C-NMR spectrum of 0.0020 to 0.0050, preferably 0.0023to 0.0045, more preferably 0.0025 to 0.0040. $\begin{matrix}{\left\lbrack M_{3} \right\rbrack = \frac{\begin{matrix}{\lbrack{Pmmrm}\rbrack + \lbrack{Pmrmr}\rbrack + \lbrack{Pmrrr}\rbrack + \lbrack{Prmrr}\rbrack +} \\{\lbrack{Prmmr}\rbrack + \lbrack{Prrrr}\rbrack}\end{matrix}}{\lbrack{Pw}\rbrack - {2\left( {\left\lbrack {S\quad {\alpha\gamma}} \right\rbrack + \left\lbrack {S\quad {\alpha\delta}^{+}} \right\rbrack} \right)} + {3\left\lbrack {T\quad \delta^{+}\delta^{+}} \right\rbrack}}} & (2)\end{matrix}$

[0393] wherein

[0394] [Pw], [Sαγ], Sα[6 ⁺] and [Tδ⁺δ⁺] have the meanings as defined inthe formula (1),

[0395] [Pmmrm] is absorption intensity of methyl groups on thirdpropylene units in five propylene unit sequences represented by ┘ ┘ ┘ ┐┐ in which ┘ and ┐ are each a propylene unit,

[0396] [Pmrmr] is absorption intensity of methyl groups on thirdpropylene units in five propylene unit sequences represented by ┘ ┘ ┐ ┐┘ in which ┘ and ┐ are each a propylene unit,

[0397] [Pmrrr] is absorption intensity of methyl groups on thirdpropylene units in five propylene unit sequences represented by ┘ ┘ ┐ ┘┐ in which ┘ and ┐ are each a propylene unit,

[0398] [Prmrr] is absorption intensity of methyl groups on thirdpropylene units in five propylene unit sequences represented by ┐ ┘ ┘ ┐┘ in which ┘ and ┐ are each a propylene unit,

[0399] [Prmmr] is absorption intensity of methyl groups on thirdpropylene units in five propylene unit sequences represented by ┐ ┘ ┘ ┘┐ in which ┘ and ┐ are each a propylene unit, and

[0400] [Prrrr] is absorption intensity of methyl groups on thirdpropylene units in five propylene unit sequences represented by ┘ ┐ ┘ ┐┘ in which ┘ and ┐ are each a propylene unit.

[0401] In the formula (2), each of [Pmmrm], [Pmrmr], [Pmrrr], [Prmrr],[Prmmr] and [Prrrr] shows absorption intensity of the methyl group onthird propylene unit in each of five propylene unit sequences which hassuch a structure that three out of five methyl groups in the fivepropylene unit sequence are the same in the direction and the residualtwo are different in the direction (such structures are referred to as“M₃ structure” hereinafter). That is, the value of the pentad tacticity[M₃] obtained from the formula (2) exhibits a proportion of the M₃structure in the propylene unit sequences.

[0402] When the boiling heptane-insoluble component of the propylenepolymer consists of only the propylene polymer units, thestereoregurality thereof can be evaluated by a value of the pentadtacticity [M3′] obtained from the following formula (2A):$\begin{matrix}{\left\lbrack M_{3^{\prime}} \right\rbrack = \frac{\begin{matrix}{\lbrack{Pmmrm}\rbrack + \lbrack{Pmrmr}\rbrack + \lbrack{Pmrrr}\rbrack + \lbrack{Prmrr}\rbrack +} \\{\lbrack{Prmmr}\rbrack + \lbrack{Prrrr}\rbrack}\end{matrix}}{\lbrack{Pw}\rbrack}} & \text{(2A)}\end{matrix}$

[0403] wherein [Pmmrm], [Pmrmr], [Pmrrr], [Prmrr], [Prmmr], [Prrrr] and[Pw] have the meanings as defined in the formula (2).

[0404] The pentad isotacticity [M₅] and the pentad tacticity [M₃] ofsuch propylene polymer are described in more detail below.

[0405] As described above, the boiling heptane-insoluble component ofthe homopolypropylene obtained by the invention desirably has the pentadisotacticity (M₅] obtained from the formula (1) of not less than 0.974,and the pentad tacticity [M₃] obtained from the formula (2) of 0.0020 to0.0050.

[0406] Such boiling heptane-insoluble component has an extremely longmesochain (i.e., propylene unit sequence in which directions of α-methylcarbons are the same as each other).

[0407] In general, polypropylene has a longer mesochain, as the value ofthe pentad tacticity [M₃] is smaller. However, when the value of thepentad isotacticity [M₅] is extremely large and the value of the pentadtacticity [M₃] is extremely small, polypropylene having a larger valueof the pentad tacticity [M₃] may have a longer mesochain with theproviso that the value of the pentad isotacticity [M₅] is almost thesame.

[0408] For example, when a polypropylene having the following structure(a) is compared with a polypropylene having the following structure (b),the polypropylene represented by the structure (a) has the M₃ structureand a longer mesochain than the polypropylene represented by thestructure (b) not having the M₃ structure. (In this example, it ispresumed that each of the structures (a) and (b) is composed of 1,003propylene units.)

[0409] The pentad isotacticity [M₅] of the polypropylene represented bythe structure (a) is 0.986, and the pentad isatacticity [M_(g)] of thepolypropylene represented by the structure (b) is 0.985, both valuesbeing almost the same. However, in the polypropylene represented by thestructure (a) having the M₃ structure, the mesochains contain 497propylene units on an average, while in the polypropylene represented bythe structure (b) not having the M₃ structure, the mesochains contain250 propylene units on an average. That is, in the polypropylene havingan extremely large value of the pentad isotacticity [M_(g)] a proportionof the structure represented by “r” (racemo) contained in the propyleneunit sequence is extremely small. Hence, such polypropylene containing alarge number of structures “r” (racemo), i.e., polypropylene having theM₃ structure, has longer mesochains as compared with the polypropylenecontaining only few structures “r” (racemo), i.e., polypropylene nothaving the M₃ structures.

[0410] The propylene polymer of the invention is a highly crystallinepolypropylene having the M₃ structures as represented by the abovestructure (a), and in this polymer, the pentad isotacticity [M_(g)] ofthe boiling heptane-insoluble component is in the range of 0.97 to0.995, and the pentad tactically [M₃] of the boiling heptane-insolublecomponent is in the range of 0.0020 to 0.0050. Such propylene polymer ofthe invention has higher rigidity, heat resistance and moistureresistance than those of the conventional highly crystallinepolypropylene.

[0411] If the pentad tacticity [M₃] of the boiling heptane-insolublecomponent is out of the range of 0.0020 to 0.0050, the propylene polymermay be deteriorated in the rigidity and the heat resistance.

[0412] In the present invention, the ¹³C-NMR measurement of the boilingheptane-insoluble component is carried out, for example, in thefollowing manner. That is, 0.35 g of the insoluble component isdissolved in 2.0 ml of hexachlorobutadiene, and the resulting solutionis filtered through a glass filter (G2). To the filtrate is added 0.5 mlof deuterated benzene, and the resulting mixture is introduced into aNMR tube having an inner diameter of 10 mm, followed by measuring the¹³C-NMR spectrum at 120° C. by the use of an NMR measuring apparatus(GX-500 type) produced by Japan Electron Optics Laboratory Co., Ltd. Thenumber of integration times is 10,000 or more.

[0413] (i-3) The boiling heptane-insoluble component of thehomopolypropylene obtained by the invention has a crystallinity, asmeasured by X-ray diffractometry, of usually not less than 60%,preferably not less than 65%, more preferably 65 to 95%, particularlypreferably 65 to 90%.

[0414] The X-ray diffractometry is carried out as follows. A sample (ofthe boiling heptane-insoluble component) is molded into a square platehaving a thickness of 1 mm by the use of a pressure molding machine of180° C., and immediately the plate is water cooled to obtain a pressedsheet. The pressed sheet is measured on its crystallinity by the use ofa Rotor Flex RU300 measuring machine produced by Rigaku Denki K.K.(output: 50 kV, 250 mA). In this measurement, a transmission method isutilized, and the measurement is conducted with rotating the sample.

[0415] As described above, the homopolypropylene obtained by theinvention desirably contains the highly isotactic boilingheptane-insoluble component (i) having the above-mentioned properties.

[0416] (ii) The amount of the 23° C. n-decane-soluble componentcontained in the homopolypropylene obtained by the invention is desiredto be not more than 5% by weight.

[0417] The homopolypropylene obtained by the invention desirably has amelt flow rate (MFR), as measured in accordance with ASTM D-1238 at 230°C. under a load of 2.16 kg, of 0.001 to 1,000 g/10 min, preferably 0.01to 500 g/10 min, more preferably 0.05 to 300 g/10 min, particularlypreferably 0.08 to 200 g/10 min.

[0418] The homopolypropylene desirably has an intrinsic viscosity [η],as measured in decahydronaphthalene at 135° C., of 0.1 to 20 dl/g,preferably 0.5 to 15 dl/g, more preferably 0.7 to 12 dl/g.

[0419] The homopolypropylene obtained by the invention may be used, ifdesired, in combination with various additives such as nucleating agent,rubber ingredient, heat stabilizer, weathering stabilizer, antistaticagent, anti-slip agent, anti-blocking agent, anti-fogging agent,lubricant, dye, pigment, natural oil, synthetic oil, wax and filler.

Process for Preparing Propylene Block Copolymer

[0420] The first process for preparing a propylene block copolymeraccording to the invention comprises the steps of polymerizing propyleneto form a polypropylene component and copolymerizing ethylene and anα-olefin of 3 to 20 carbon atoms to form an ethylene/α-olefin copolymercomponent, in an optional order, wherein both of the polymerizing andcopolymerizing steps are carried out in the presence of the olefinpolymerization catalyst (1) formed from:

[0421] [I-1] the contact product obtained by contacting:

[0422] (A) the solid titanium catalyst component,

[0423] (B) the organometallic compound catalyst component, and

[0424] (C) the organosilicon compound;

[0425] (D) the compound having at least two ether linkages presentthrough plural atoms; and optically,

[0426] [II-1]

[0427] [III] the organometallic compound catalyst component, asdescribed above.

[0428] In the first process for preparing a propylene block copolymeraccording to the invention, in place of the olefin polymerizationcatalyst (1), there can be used the olefin polymerization catalyst (1 a)formed from:

[0429] [Ia-1] the prepolymerized catalyst component obtained byprepolymerizing an olefin of 2 or more carbon atoms in the presence ofthe catalyst components for forming the contact product [I-1] in such away that the amount of the prepolymer formed is 0.01 to 2,000 g based on1 g of the solid titanium catalyst component (A);

[0430] [II-1] (D) the compound having at least two ether linkagespresent through plural atoms; and optionally,

[0431] [III] the organometallic compound catalyst component.

[0432] In the first process for preparing a propylene block copolymeraccording to the invention, a propylene block copolymer havingproperties as described later can be prepared.

[0433] An example of the process for preparing a propylene blockcopolymer according to the invention is a process comprising initiallypolymerizing propylene to form a polypropylene component and thencopolymerizing ethylene and an α-olefin of 3 to 20 carbon atoms to forman ethylene/α-olefin copolymer component, in the presence of the olefinpolymerization catalyst.

[0434] Another example thereof is a process comprising initiallycopolymerizing ethylene and an α-olefin of 3 to 20 carbon atoms to forman ethylene/α-olefin copolymer component and then polymerizing propyleneto form a polypropylene component, in the presence of the olefinpolymerization catalyst.

[0435] In this invention, preferred is the process comprising initiallyforming a polypropylene component and then forming an ethylene/α-olefincopolymer component, and this process will be mainly describedhereinafter.

Preparation of Polypropylene Component

[0436] In the process for preparing a propylene block copolymeraccording to the invention, propylene is polymerized in the presence ofthe olefin polymerization catalyst (1) or (1 a) to prepare polypropylenecomponent.

[0437] In the present invention, it is preferred to polymerize onlypropylene in the preparation of polypropylene component, but propylenemay be copolymerized with a small amount of other α-olefin thanpropylene, with the proviso that the objects of the invention are notmarred.

[0438] Examples of the other α-olefins copolymerizable with propyleneinclude ethylene and α-olefins of 4 to 20 carbon atoms such as 1-butene,1-pentene, 1-hexene, 1-octene, 1-decene, 1-dodecene, 1-tetradecene,1-hexadecene, 1-octadecene, 1-eicosene, 3-methyl-1-butene,3-methyl-1-pentene, 3-ethyl-1-pentene, 4-methyl-1-pentene,4-methyl-1-hexene, 4,4-dimethyl-1-hexene, 4,4-dimethyl-1-pentene,4-ethyl-1-hexene and 3-ethyl-1-hexene.

[0439] Also employable are other olefins than α-olefins, such as thoseused for the prepolymerization, and diene compounds described later forpreparing an ethylene/α-olefin copolymer component of the propyleneblock copolymer.

[0440] The olefin other than propylene is used in such an amount thatthe units derived therefrom are finally present in an amount of not morethan 5% by mol, preferably not more than 4% by mol, in the resultingpolypropylene.

[0441] In the present invention, the polymerization of propylene can becarried out in two or more steps under different reaction conditions.

[0442] The polymerization may be performed by a solvent suspensionpolymerization process, a suspension polymerization process using liquidpropylene as a solvent, a gas phase polymerization process or the like.

[0443] In the solvent suspension polymerization process, a hydrocarbonwhich is polymerization-inactive can be used as a polymerizationsolvent. For example, hydrocarbons described with respect to theprepolymerization, particularly aliphatic hydrocarbons, can be employed.

[0444] In the polymerization system, the contact product [I-1] or theprepolymerized catalyst component [Ia-1] is used in an amount of usuallyabout 0.0001 to 50 mmol, preferably about 0.001 to 10 mmol, in terms oftitanium atom, based on 1 liter of the polymerization volume. Theelectron donor [II-1] (polyether compound (D)) is used in an amount ofusually 0.001 to 5,000 mol, preferably 0.01 to 1,000 mol, based on 1 molof the titanium atom. The organometallic compound catalyst component[III] is used, optically, in an amount of usually 1 to 2;000 mol,preferably 2 to 1,000 mol, based on 1 mol of the titanium atom in thepolymerization system.

[0445] The polymerization of propylene may be carried out at atemperature of usually about −50 to 200° C., preferably about 50 to 100°C., and a pressure of usually atmospheric pressure to 100 kg/cm²,preferably about 2 to 50 kg/cm.

[0446] The polymerization of propylene can be carried out eitherbatchwise, semi-continuously or continuously.

[0447] In the polymerization of propylene, hydrogen (chain transferagent) may be used to regulate a molecular weight of the resultingpolypropylene. In this invention, it is desired to use hydrogen in anamount of not more than 0.5 mol, preferably not more than 0.4 mol, morepreferably not more than 0.3 mol, based on 1 mol of propylene, althoughthe amount varies depending on the molecular weight of the resultingpolymer.

[0448] In the process for preparing polypropylene component using theolefin polymerization catalyst (1) or (1 a) according to the invention,polypropylene component having a high melt flow rate and a highisotacticity can be prepared by the use of a small amount of hydrogen.

[0449] The polypropylene component obtained desirably has a melt flowrate (MFR), as measured in accordance with ASTM D-1238 at 230° C. undera load of 2.16 kg, of 0.001 to 1,000 g/10 min, preferably 0.01 to 500g/10 min, more preferably 0.08 to 200 g/10 min.

[0450] The polypropylene component desirably has an intrinsic viscosity[η], as measured in decahydronaphthalene at 135° C., of 0.1 to 20 dl/g,preferably 0.5 to 15 dl/g, more preferably 0.7 to 12 dl/g.

[0451] The polypropylene component desirably contains the 23° C.n-decane-soluble component in an amount of usually not more than 5% byweight, preferably not more than 3% by weight, more preferably not morethan 2% by weight, particularly preferably not more than 1.5% by weight.

Preparation of Ethylene/α-olefin Copolymer Component

[0452] In the present invention, after preparing the polypropylenecomponent as described above, ethylene and an α-olefin of 3 to 20 carbonatoms are copolymerized in the presence of the polypropylene componentobtained and without deactivation of the catalyst used for preparing thepolypropylene component, to prepare an ethylene/α-olefin copolymercomponent.

[0453] Examples of the α-olefins of 3 to 20 carbon atoms copolymerizablewith ethylene include propylene, 1-butene, 1-pentene, 1-hexene,1-octene, 1-decene, 1-dodecene, 1-tetradecene, 1-hexadecene,1-octadecene, 1-eicosene, 3-methyl-1-butene, 3-methyl-1-pentene,3-ethyl-1-pentene, 4-methyl-1-pentene, 4-methyl-1-hexene,4,4-diemthyl-1-hexene, 4,4-dimethyl-1-pentene, 4-ethyl-1-hexene and3-ethyl-1-hexene.

[0454] Preferred as the α-olefins copolymerizable with ethylene arepropylene, 1-butene and 1-pentene. These α-olefins may be used incombination of two or more kinds.

[0455] In this copolymerization, in addition to the above α-olefins, theolefins which are described before with respect to the prepolymerizationand diene compounds can be employed.

[0456] Examples of the diene compounds include 1,3-butadiene,1,3-pentadiene, 1,4-pentadiene, 1,3-hexadiene, 1,4-hexadiene,1,5-hexadiene, 4-methyl-1,4-hexadiene, 5-methyl-1,4-hexadiene,6-methyl-1,6-octadiene, 7 methyl-1,6-octadiene, 6-ethyl-1,6-octadiene,6-propyl-1,6-octadiene, 6-butyl-1,6-octadiene, 6-methyl-1,6-nonadiene,7-methyl-1,6-nonadiene, 6-ethyl-1,6-nonadiene, 7-ethyl-1,6-nonadiene,6-methyl-1,6-decadiene, 7-methyl-1,6-decadiene, 6-methyl-1,6-decadiene,1,7-octadiene, 1,9-decadiene, isoprene, butadiene, ethylidenenorbornene,vinylnorbornene and dicyclopentadiene. These diene compounds may be usedin combination of two or more kinds.

[0457] In the copolymerization system, the polypropylene component isused in an amount of 10 to 1,000 g, preferably 10 to 800 g, particularlypreferably 30 to 500 g, based on 1 liter of the polymerization volume.This polypropylene is desirably present in the system in an amount ofusually 0.0001 to 1 mmol, preferably about 0.001 to 0.5 mmol, in termsof titanium atom of the solid titanium catalyst component (A) containedin the polypropylene, based on 1 liter of the polymerization volume.

[0458] After the propylene component is prepared as described above, inthe copolymerising ethylene and the α-olefin of 3 to 20 carbon atoms,the catalyst components may be further added to the copolymerizationsystem.

[0459] For example, in the first process for preparing a propylene blockcopolymer, the solid titanium catalyst component (A), the electron donor[II-1] (polyether compound (D)) and the organometallic compound catalystcomponent [III] can be added. In this case, the solid titanium catalystcomponent (A) can be used in an amount of 0.0001 to 20 mmol, preferably0.001 to 20 mmol, based on 1 liter of the polymerization volume. Theelectron donor [II-1] can be used in an amount of 0.001 to 5,000 mol,preferably 0.01 to 1,000 mol, based on 1 mol of the titanium atom in thepolymerization system. The organometallic compound catalyst component[III] can be used in an amount of 1 to 2,000 mol, preferably about 2 to1,000 mol, based on 1 mol of the titanium atom in the polymerizationsystem.

[0460] The copolymerization of ethylene and the α-olefin can be carriedout in a gas phase or a liquid phase.

[0461] In the case where the copolymerization is performed by a solventsuspension polymerization process, the aforesaid inert hydrocarbon canbe used as a polymerization solvent.

[0462] In the copolymerization, hydrogen (chain transfer agent) can beadded, if desired, to regulate a molecular weight of the resultingcopolymer.

[0463] The copolymerization can be carried out at a temperature ofusually about −50 to 200° C., preferably about 20 to 100° C., and apressure of usually atmospheric pressure to 100 kg/cm², preferably about2 to 50 kg/cm².

[0464] The copolymerization may be carried out either batchwise,semi-continuously or continuously. Further, the copolymerization can beconducted in two or more stages under different reaction conditions.

[0465] In the ethylene/α-olefin copolymerization step described above,an ethylene/α-olefin copolymer component having a high molecular weightcan be easily obtained.

[0466] According to the first process for preparing a propylene blockcopolymer as mentioned above, a propylene block copolymer containing ahighly isotactic polypropylene component and containing a rubbercomponent of high molecular weight (high intrinsic viscosity [η]) can beeasily prepared.

[0467] Next, the second to fifth processes for preparing a propyleneblock copolymer using a specific olefin polymerization catalyst aredescribed. Properties of the propylene block copolymer which can beobtained by these processes are described later.

[0468] The solid titanium catalyst component (A), the organometalliccompound catalyst component (B) (or (III)), the organosilicon compound(C) represented by the formula (c-i), and the compound (D) having atleast two ether linkages spaced by plural atoms (polyether compound)(D),and the organosilicon compound (E) represented by the formula (c-iii)are the same as those used for preparing the olefin polymerizationcatalyst (1).

[0469] The second process for preparing a propylene block copolymeraccording to the invention comprises the steps of polymerizing propyleneto form a polypropylene component and copolymerizing ethylene and anα-olefin of 3 to 20 carbon atoms to form an ethylene/α-olefin copolymercomponent, in an optional order, wherein both of the polymerization andcopolymerization steps are carried out in the presence of an olefinpolymerization catalyst (2) formed from:

[0470] [I-2] a contact product obtained by contacting:

[0471] (A) the solid titanium catalyst component,

[0472] (B) the organometallic compound catalyst component, and

[0473] (D) the compound having at least two ether linkages spaced byplural atoms;

[0474] [II-2] (C) the organosilicon compound represented by the formula(c-i); and optionally,

[0475] [III] the organometallic compound catalyst component.

[0476] Through this process, a specific propylene block copolymerdescribed later is prepared.

[0477] In the second process for preparing a propylene block copolymeraccording to the invention, in place of the olefin polymerizationcatalyst (2), there can be used an olefin polymerization catalyst (2 a)formed from:

[0478] [Ia-2] a prepolymerized catalyst component obtained byprepolymerizing an olefin of 2 or more carbon atoms in the presence ofthe catalyst components for forming the contact product [I-1] in such away that the amount of the prepolymer formed is 0.01 to 2,000 g based on1 g of the solid titanium catalyst component (A);

[0479] [II-2] (C) the organosilicon compound represented by the formula(c-i); and optionally,

[0480] [III] the organometallic compound catalyst component.

[0481] In the propylene polymerization step of the second process forpreparing a propylene block copolymer, the contact product [I-2] or theprepolymerized catalyst component [Ia-2] is used in an amount of usuallyabout 0.0001 to 50 mmol, preferably about 0.001 to 10 mmol, in terms oftitanium atom, based on 1 liter of the polymerization volume.

[0482] The electron donor [II-2] (organosilicon compound (C)) is used inan amount of usually 0.001 to 5,000 mol, preferably 0.01 to 1,000 mol,based on 1 mol of the titanium atom. The organometallic compoundcatalyst component [III] is used, optionally, in an amount of usually 1to 2,000 mol, preferably 2 to 1,000 mol, based on 1 mol of the titaniumatom in the polymerization system.

[0483] In this propylene polymerization step, the same copolymerizablemonomers as used for the first process for preparing a propylene blockcopolymer can be employed. The polymerization conditions such as atemperature, a pressure and a procedure may be the same as those for thefirst process for preparing a propylene block copolymer.

[0484] If propylene is polymerized in the presence of the olefinpolymerization catalyst (2) or (2 a), a highly isotactic polypropylenecomponent can be prepared. Moreover, molecular weight regulation bymeans of hydrogen can be easily made, and hence a polypropylenecomponent having a high melt flow rate can be prepared by the use of asmall amount of hydrogen.

[0485] The polypropylene component prepared in the propylenepolymerization step has the same properties (MRF, intrinsic viscosity[η], 23° C. n-decane-soluble component, etc.) as those of thepolypropylene component prepared in the first process for preparing apropylene block copolymer.

[0486] In the ethylene/α-olefin copolymerization step, the polypropylenecomponent is used in an amount of 10 to 1,000 g, preferably 10 to 800 g,particularly preferably 30 to 500 g, based on 1 liter of thepolymerization volume. This polypropylene is desirably present in anamount of usually 0.0001 to 1 mmol, preferably about 0.001 to 0.5 mmol,in terms of titanium atom of the solid titanium catalyst component (A)contained in the polypropylene, based on 1 liter of the polymerizationvolume.

[0487] To the ethylene/α-olefin copolymerization system, the solidtitanium catalyst component (A), the electron donor [II-2](organosilicon compound (C)) and the organometallic compound catalystcomponent [III] can be further added. In this case, the solid titaniumcatalyst component (A) can be used in an amount of 0.0001 to 20 mmol,preferably 0.001 to 20 mmol, based on 1 liter of the polymerizationvolume. The electron donor [II-2] can be used in an amount of 0.001 to5,000 mol, preferably 0.01 to 1,000 mol, based on 1 mol of the titaniumatom in the polymerization system. The organometallic compound catalystcomponent [III] can be used in an amount of 1 to 2,000 mol, preferablyabout 2 to 1,000 mol, based on 1 mol of the titanium atom in thepolymerization system.

[0488] In the ethylene/α-olefin copolymerization step described above,an ethylene/α-olefin copolymer component having a high molecular weightcan be easily obtained.

[0489] According to the second process for preparing a propylene blockcopolymer as mentioned above, a propylene block copolymer containing ahighly isotactic polypropylene component and containing a rubbercomponent of high molecular weight (high intrinsic viscosity [η]) can beeasily prepared.

[0490] The third process for preparing a propylene block copolymeraccording to the invention comprises the steps of polymerizing propyleneto form a polypropylene component and copolymerizing ethylene and anα-olefin of 3 to 20 carbon atoms to form an ethylene/α-olefin copolymercomponent, in an optional order, wherein both of the polymerization andcopolymerization steps are carried out in the presence of an olefinpolymerization catalyst (3) formed from:

[0491] [I-3] a contact product obtained by contacting:

[0492] (A) the solid titanium catalyst component,

[0493] (B) the organometallic compound catalyst component, and

[0494] (D) the compound having at least two ether linkages presentthrough plural atoms;

[0495] (D) the compound having at least two ether linkages presentthrough plural atoms; and optionally,

[0496] [II-3]

[0497] [III] the organometallic compound catalyst component.

[0498] Through this process, a specific propylene block copolymerdescribed later is prepared.

[0499] In the third process for preparing a propylene block copolymeraccording to the invention, in place of the olefin polymerizationcatalyst (3), there can be used an olefin polymerization catalyst (3 a)formed from:

[0500] [Ia-3] a prepolymerized catalyst obtained by prepolymerizing anolefin of 2 or more carbon atoms in the presence of the catalystcomponents for forming the contact product [I-3] in such a way that theamount of the prepoymer formed is 0.01 to 2,000 g based on 1 g of thesolid titanium catalyst component (A);

[0501] [II-3] (D) the compound having at least two ether linkagespresent through plural atoms; and optionally,

[0502] [III] the organometallic compound catalyst component.

[0503] This prepolymerized catalyst component [1a-3] for forming theolefin polymerization catalyst (3 a) is the same as the prepolymerizedcatalyst component [Ia-2] for forming the olefin polymerization catalyst(2 a).

[0504] When the prepolymerized catalyst or the olefin polymerizationcatalyst for use in the third process for preparing a propylene blockcopolymer is formed from the above components, other components usefulfor the catalyst formation may be used. For example, the electron donors(a) and (b) described before with respect to the preparation of theolefin polymerization catalyst (1) can be used.

[0505] In the propylene polymerization step of the third process forpreparing a propylene block copolymer, the contact product [I-3] or theprepolymerized catalyst component [Ia-3] is used in an amount of usuallyabout 0.0001 to 50 mmol, preferably about 0.001 to 10 mmol, in terms oftitanium atom, based on 1 liter of the polymerization volume. Theelectron donor [II-3] (polyether compound (D)) is used in an amount ofusually 0.001 to 5,000 mol, preferably 0.01 to 1,000 mol, based on 1 molof the titanium atom. The organometallic compound catalyst component[III] is used, optionally, in an amount of usually 1 to 2,000 mol,preferably 2 to 1,000 mol, based on 1 mol of the titanium atom in thepolymerization system.

[0506] In this propylene polymerization step, the same copolymerizablemonomers as used for the first process for preparing a propylene blockcopolymer can be employed. The polymerization conditions such as atemperature, a pressure and a procedure may be the same as those for thefirst process for preparing a propylene block copolymer.

[0507] If propylene is polymerized in the presence of the olefinpolymerization catalyst (3) or (3 a), a highly isotactic polypropylenecomponent can be prepared. Moreover, molecular weight regulation bymeans of hydrogen can be easily made, and hence a polypropylenecomponent having a high melt flow rate can be prepared by the use of asmall amount of hydrogen.

[0508] The polypropylene component prepared in this propylenepolymerization step has the same properties as those of thepolypropylene component prepared in the first process for preparing apropylene block copolymer.

[0509] In the ethylene/α-olefin copolymerization step, the polypropylenecomponent is used in an amount of 10 to 1,000 g, preferably 10 to 800 g,particularly preferably 30 to 500 g, based on 1 liter of thepolymerization volume. This polypropylene is desirably present in anamount of usually 0.0001 to 1 mmol, preferably about 0.001 to 0.5 mmol,in terms of titanium atom of the solid titanium catalyst component (A)contained in the polypropylene, based on 1 liter of the polymerizationvolume.

[0510] To the ethylene/α-olefin copolymerization system, the solidtitanium catalyst component (A), the electron donor [II-3] (polyethercompound (D)) and the organometallic compound catalyst component [III]can be further added. In this case, the solid titanium catalystcomponent (A) can be used in an amount of 0.0001 to 20 mmol, preferably0.001 to 20 mmol, based on 1 liter of the polymerization volume. Theelectron donor [II-3] (polyether compound (D)) can be used in an amountof 0.001 to 2,000 mol, preferably 0.01 to 1,000 mol, based on 1 mol ofthe titanium atom in the polymerization system. The organometalliccompound catalyst component [III] can be used in an amount of 1 to 2,000mol, preferably about 2 to 1,000 mol, based on 1 mol of the titaniumatom in the polymerization system.

[0511] In the ethylene/α-olefin copolymerization step described above,an ethylene/α-olefin copolymer component having a high molecular weightcan be easily obtained.

[0512] According to the third process for preparing a propylene blockcopolymer as mentioned above, a propylene block copolymer containing ahighly isotactic polypropylene component and containing a rubbercomponent of high molecular weight (high intrinsic viscosity [η] can beeasily prepared.

[0513] The fourth process for preparing a propylene block copolymeraccording to the invention comprises the steps of polymerizing propyleneto form a polypropylene component and copolymerizing ethylene and anα-olefin of 3 to 20 carbon atoms to form an ethylene/α-olefin copolymercomponent, in an optional order, wherein both of the polymerization andcopolymerization steps are caarried out in the presence of an olefinpolymerization catalyst (4) formed from:

[0514] [I-4] (A-2) a solid titanium catalyst component comprisingmagnesium, titanium, halogen and (D) a compound having at least twoether linkages spaced by plural atoms;

[0515] [II-4] (C) the organosilicon compound represented by the formula(c-i) and/or (D) the compound having at least two ether linkages spacedby plural atoms; and

[0516] [III] the organometallic compound catalyst component.

[0517] Through this process, a specific propylene block copolymerdescribed later is prepared.

[0518] In the fourth process for preparing a propylene block copolymeraccording to the invention, in place of the olefin polymerizationcatalyst (4), there can be used an olefin polymerization catalyst (4 a)formed from:

[0519] [Ia-4] a prepolymerized catalyst component obtained byprepolymerizing an olefin of 2 or more carbon atoms in the presence ofthe solid titanium catalyst component (A-2) and the organometalliccompound catalyst component (B) in such a way that the amount of theprepolymer formed is 0.01 to 2,000 g based on 1 g of the solid titaniumcatalyst component (A-2);

[0520] [II-4] (C) the organosilicon compound represented by the formula(c-i) and/or (D) the compound having at least two ether linkages spacedby plural atoms; and optionally,

[0521] [III] the organometallic compound catalyst component.

[0522] The solid titanium catalyst component (A-2) used for preparingthe olefin polymerization catalyst (4) or (4 a) can be prepared in thesame manner as described in the preparation of the solid titaniumcatalyst component (A) except that the polyether compound (D) (electrondonor) is used as the essential component. In more detail, the solidtitanium catalyst component (A-2) can be prepared by bringing themagnesium compound, the titanium compound (both described before withrespect to the preparation of the solid titanium catalyst component (A))and the polyether compound (D) into contact with each other. In thepreparation of the solid titanium catalyst component (A-2), othercompounds than the polyether compound (D) among the compoundsexemplified as the electron donor (a) can be used in combination withthe polyether compound(D).

[0523] The amount of each of the components used for forming the solidtitanium catalyst component (A-2) varies depending on the process used,and cannot be defined in general. However, for example, the polyethercompound (D) is used in an amount of 0.01 to 5 mol, preferably 0.1 to 1mol, based on 1 mol of the magnesium compound, and other electron donoris used, if desired, in an amount of 0.01 to 98 1,000 mol, preferably0.1 to 200 mol, based on 1 mol of the magnesium compound.

[0524] The solid titanium catalyst component (A-2) contains magnesium,titanium, halogen and the polyether compound (D), and in this solidtitanium catalyst component (A-2), an atomic ratio of halogen/titaniumis in the range of about 2 to 200, preferably about 4 to 100; a molarratio of the polyether compound (D)/titanium is in the range of about0.01 to 100, preferably about 0.2 to 10; and an atomic ratio ofmagnesium/titanium is in the range of about 1 to 100, preferably about 2to 50.

[0525] The prepolymerized catalyst component [Ia-4] can be prepared inthe same manner as described in the preparation of the prepolymerizedcatalyst [Ia-1] except that the organosilicon compound (C) is not used.

[0526] In the preparation of the prepolymerized catalyst [Ia-4], thesolid titanium catalyst component (A-2) is used in an amount of usuallyabout 0.0001 to 200 mmol, preferably about 0.001 to 100 mmol, in termsof titanium atom, based on 1 liter of the polymerization volume. Theorganometallic compound catalyst component (B) is used in an amount ofusually 0.01 to 100 mol, preferably 0.5 to 50 mol, based on 1 mol of thetitanium atom.

[0527] The same olefins of 2 or more carbon atoms as used for preparingthe prepolymerized catalyst [1a-1] can be used for preparing theprepolymerized catalyst [1a-4]. Among those olefins, preferred areethylene, propylene, 1-butene, 1-pentene, 3-methyl-1-butene,3-methyl-1-pentene, 3-ethyl-1-hexene, vinylcyclohexane,allyltrimethylsilane and dimethylstyrene, and of these, more preferredare propylene, 3-methyl-1-butene, vinylcyclohexane andallyltrimethylsilane. These olefins may be used in combination of two ormore kinds.

[0528] The prepolymerization is desirably carried out in such a mannerthat a prepolymer is produced in an amount of 0.01 to 2,000 g,preferably 0.1 to 200 g, based on 1 g of the solid titanium catalystcomponent (A-2).

[0529] When the prepolymerized catalyst or the olefin polymerizationcatalyst for use in the fourth process for preparing a propylene blockcopolymer is formed from the above components, other components usefulfor the catalyst formation may be used in combination with the abovecomponents. For example, the electron donors (a) and (b) describedbefore with respect to the preparation of the olefin polymerizationcatalyst (1) can be used, if desired.

[0530] In the propylene polymerization step using the olefinpolymerization catalyst (4), the solid titanium catalyst component (A-2)([I-4]) is used in an amount of usually about 0.0001 to 50 mmol,preferably about 0.001 to 10 mmol, in terms of titanium atom, based on 1liter of the polymerization volume. The electron donor [II-4](organosilicon compound (C) and/or polyether compound (D)) is used in anamount of usually 0.001 to 5,000 mol, preferably 0.01 to 1,000 mol,based on 1 mol of the titanium atom in the polymerization system. Theorganometallic compound catalyst component [III] is used in an amount ofusually 1 to 2,000 mol, preferably 2 to 1,000 mol, based on 1 mol of thetitanium atom.

[0531] In the propylene polymerization step using the olefinpolymerization catalyst (4 a), the prepolymerized catalyst [Ia-4] isused in an amount of usually about 0.0001 to 50 mmol, preferably about0.001 to 10 mmol, in terms of titanium atom, based on 1 liter of thepolymerization volume. The electron donor [II-4] (organosilicon compound(C) and/or polyether compound (D)) is used in an amount of usually 0.001to 5,000 mol, preferably 0.001 to 1,000 mol, based on 1 mol of thetitanium atom in the polymerization system. The organometallic compoundcatalyst component [III] is used in an amount of usually 1 to 2,000 mol,preferably 2 to 1,000 mol, based on 1 mol of the titanium atom.

[0532] In this propylene polymerization step, the same copolymerizablemonomers as used for the first process for preparing a propylene blockcopolymer can be employed. The polymerization conditions such as atemperature, a pressure and a procedure may be the same as those for thefirst process for preparing a propylene block copolymer.

[0533] If propylene is polymerized in the presence of the olefinpolymerization catalyst (4) or (4 a), a highly isotactic polypropylenecomponent can be prepared. Moreover, molecular weight regulation bymeans of hydrogen can be easily made, and hence a polypropylenecomponent having a high melt flow rate can be prepared by the use of asmall amount of hydrogen.

[0534] In the propylene polymerization step of the fourth process forpreparing a propylene block copolymer, a polypropylene component can beobtained in an amount of 5,000 to 300,000 g, preferably 10,000 to200,000 g, based on 1 g of the solid titanium catalyst component (A-2),though the amount varies depending on the polymerization conditions.

[0535] The polypropylene component prepared in this propylenepolymerization step has the same properties as those of thepolypropylene component prepared in the first process for preparing apropylene block copolymer.

[0536] In the ethylene/α-olefin copolymerization step, the polypropylenecomponent is used in an amount of 10 to 1,000 g, preferably 10 to 800 g,particularly preferably 30 to 500 g, based on 1 liter of thepolymerization volume. This polypropylene is desirably present in anamount of usually 0.0001 to 1 mmol, preferably about 0.001 to 0.5 mmol,in terms of titanium atom of the solid titanium catalyst component (A-2)contained in the polypropylene, based on 1 liter of the polymerizationvolume.

[0537] To the ethylene/α-olefin copolymerization system, the solidtitanium catalyst component (A-2), the electron donor [II-4](organosilicon compound (C) and/or polyether compound (D)) and theorganometallic compound catalyst component [III] can be further added.In this case, the solid titanium catalyst component (A-2) can be used inan amount of 0.0001 to 30 mmol, preferably 0.001 to 5 mmol, based on 1liter of the polymerization volume. The electron donor [II-4](organosilicon compound (C) and/or polyether compound (D)) can be usedin an amount of 0.001 to 5,000 mol, preferably 0.01 to 1,000 mol, basedon 1 mol of the titanium atom in the polymerization system. Theorganometallic compound catalyst component [III] can be used in anamount of 1 to 2,000 mol, preferably about 2 to 1,000 mol, based on 1mol of the titanium atom in the polymerization system.

[0538] In the ethylene/α-olefin copolymerization step described above,an ethylene/α-olefin copolymer component having a high molecular weightcan be easily obtained.

[0539] According to the fourth process for preparing a propylene blockcopolymer as mentioned above, a propylene block copolymer containing ahighly isotactic polypropylene component and containing a rubbercomponent of high molecular weight (high intrinsic viscosity [η]) can beeasily prepared.

[0540] The fifth process for preparing a propylene block copolymeraccording to the invention comprises the steps of polymerizing propyleneto form a polypropylene component and copolymerizing ethylene and anα-olefin of 3 to 20 carbon atoms to form an ethylene/α-olefin copolymercomponent, in an optional order, wherein both of the polymerizing andcopolymerizing steps are carried out in the presence of an olefinpolymerization catalyst (5 a) formed from:

[0541] [Ia-5] a prepolymerized catalyst component obtained byprepolymerizing an olefin of 2 or more carbon atoms in the presence of

[0542] (A) the solid titanium catalyst component,

[0543] (B) the organometallic compound catalyst component, and

[0544] (E) an organosilicon compound represented by the followingformula (c-iii)

R_(n)Si(OR′)_(4−n)  (c-iii)

[0545] wherein R and R′ are each a hydrocarbon group, and n is a numbersatisfying the condition of 0<n<4, in such a way that the amount of theprepolymer formed is 0.01 to 2,000 g based on 1 g of the solid titaniumcatalyst component (A);

[0546] [II-5] (C) the organosilicon compound represented by the formula(c-i); and optionally,

[0547] [III] the organometallic compound catalyst component.

[0548] Through this process, a specific propylene block copolymerdescribed later is prepared.

[0549] The organosilicon compound (E) represented by the above formula(c-iii) may be the same as the organosilicon compound (C) represented bythe formula (c-i) described before with respect to the polymerizedcatalyst [Ia-1], but the compound (E) is preferably the same as thecompound (C).

[0550] The prepolymerized catalyst [Ia-5] can be prepared in the samemanner as described in the preparation of the prepolymerized catalyst[Ia-1] except that the organosilicon compound (E) represented by theformula (c-iii) is used in place of the organosilicon compound (C)represented by the formula (c-i).

[0551] The same olefins of 2 or more carbon atoms as used for preparingthe prepolymerized catalyst [1a-1] can be used for preparing theprepolymerized catalyst [1a-5].

[0552] Among those olefins, preferred as the prepolymerizable monomersfor preparing the prepolymerized catalyst [Ia-5] are propylene,1-butene, 1-pentene, 3-methyl-1-butene, 3-methyl-1-pentene,3-ethyl-1-hexene, vinylcyclohexane, allyltrimethylsilane anddimethylstyrene, and of these, more preferred are propylene,3-methyl-1-butene and vinylcyclohexane, allyltrimethylsilane. Theseolefins may be used in combination of two or more kinds.

[0553] When a linear olefin is used as the prepolymerizable monomer, theorganosilicon compound (C) represented by the formula (c-i) ispreferably used as the organosilicon compound (E) represented by theformula (c-iii). When a branched olefin is used as the prepolymerizablemonomer, an organosilicon compound having a lower alkyl group or a loweralkoxy group is preferably used as the organosilicon compound (E)represented by the formula (c-iii).

[0554] Specific examples of the organosilicon compounds having a loweralkyl group or a lower alkoxy group include:

[0555] trimethylmethoxysilane, trimethylethoxysilane,dimethyldimethoxysilane, dimethyldiethoxysilane,diisopropyldimethoxysilane, diphenyldimethoxysilane,phenylmethyldimethoxysilane, diphenyldiethoxysilane,bis-o-tolyldimethoxysilane, bis-m-tolyldimethoxysilane,bis-p-tolyldimethoxysilane, bis-p-tolyldiethoxysilane,bis-ethylphenyldimethoxysilane, ethyltrimethoxysilane,ethyltriethoxysilane, vinyltrimethoxysilane, methyltrimethoxysilane,n-propyltriethoxysilane, decyltrimethoxysilane, decyltriethoxysilane,phenyltrimethoxysilane, γ-chloropropyltrimethoxysilane,methyltriethoxysilane, ethyltriethoxysilane, vinyltriethoxysilane,n-butyltriethoxysilane, phenyltriethoxysilane,γ-aminopropyltriethoxysilane, chlorotriethoxysilane,ethyltriisopropoxysilane, vinyltributoxysilane, ethyl silicate, butylsilicate, trimethylphenoxysilane, methyltriallyoxysilane,vinyltris(β-methoxyethoxysilane), vinyltriacetoxysilane anddimethyltetraethoxysiloxane.

[0556] The prepolymerization is desirably carried out in such a mannerthat a prepolymer is produced in an amount of 0.01 to 2,000 g,preferably 0.1 to 500 g, based on 1 g of the solid titanium catalystcomponent (A).

[0557] When the prepolymerized catalyst or the olefin polymerizationcatalyst for use in the fifth process for preparing a propylene blockcopolymer is formed from the above components, other components usefulfor the catalyst formation may be used in combination with the abovecomponents. For example, the electron donors (a) and (b) describedbefore with respect to the preparation of the olefin polymerizationcatalyst (1) can be used, if desired. In the propylene polymerizationstep using the olefin polymerization catalyst (5 a), the prepolymerizedcatalyst [Ia-5] is used in an amount of usually about 0.0001 to 2 mmol,preferably about 0.001 to 1 mmol, in terms of titanium atom, based on 1liter of the polymerization volume. The electron donor [II-5](organosilicon compound (C)) is used in an amount of usually 0.001 to5,000 mol, preferably 0.01 to 1,000 mol, based on 1 mol of the titaniumatom. The organometallic compound catalyst component [III] is used,optionally, in an amount of usually 1 to 2,000 mol, preferably 2 to1,000 mol, based on 1 mol of the titanium atom in the polymerizationsystem.

[0558] In this propylene polymerization step, the same copolymerizablemonomers as used for the first process for preparing a propylene blockcopolymer can be employed. The polymerization conditions such as atemperature, a pressure and a procedure may be the same as those for thefirst process for preparing a propylene block copolymer.

[0559] If propylene is polymerized in the presence of the olefinpolymerization catalyst (5 a), a highly isotactic polypropylenecomponent can be prepared.

[0560] The polypropylene component prepared in this propylenepolymerization step has the same properties as those of thepolypropylene component prepared in the first process for preparing apropylene block copolymer.

[0561] In the ethylene/α-olefin copolymerization step, the polypropylenecomponent is used in an amount of 10 to 1,000 g, preferably 10 to 800 g,particularly preferably 30 to 500 g, based on 1 liter of thepolymerization volume. This polypropylene is desirably present in anamount of usually 0.0001 to 1 mmol, preferably about 0.001 to 0.5 mmol,in terms of titanium atom of the solid titanium catalyst component (A)contained in the polypropylene, based on 1 liter of the polymerizationvolume.

[0562] To the ethylene/α-olefin copolymerization system, the solidtitanium catalyst component (A), the electron donor [II-5](organosilicon compound (C)) and the organometallic compound catalystcomponent [III] can be further added. In this case, the solid titaniumcatalyst component (A) can be used in an amount of 0.0001 to 20 mmol,preferably 0.001 to 20 mmol, based on 1 liter of the polymerizationvolume. The electron donor [II-5] (organosilicon compound (C)) can beused in an amount of 0.001 to 5,000 mol, preferably 0.01 to 1,000 mol,based on 1 mol of the titanium atom in the polymerization system. Theorganometallic compound catalyst component [III] can be used in anamount of 1 to 2,000 mol, preferably about 2 to 1,000 mol, based on 1mol of the titanium atom in the polymerization system.

[0563] In the ethylene/α-olefin copolymerization step described above,an ethylene/α-olefin copolymer component having a high molecular weightcan be easily obtained.

[0564] According to the fifth process for preparing a propylene blockcopolymer as mentioned above, a propylene block copolymer containing ahighly isotactic polypropylene component and containing a rubbercomponent of high molecular weight (high intrinsic viscosity [η]) can beeasily prepared.

[0565] In the first to fifth processes for preparing a propylene blockcopolymer according to the invention, an yield of the propylene blockcopolymer per unit amount of the solid titanium catalyst component ishigh, and hence the amount of the catalyst residue (particularly halogencontent) in the product can be relatively reduced. Accordingly, anoperation for removing the catalyst residue contained in the product canbe omitted, and moreover, a mold can be effectively prevented fromoccurrence of rust in the molding process of the resulting propyleneblock copolymer.

Propylene Block Copolymer

[0566] According to the processes for preparing a propylene blockcopolymer as mentioned above, a propylene block copolymer having thefollowing properties can be obtained.

[0567] The propylene block copolymer obtained by the invention desirablycontains a boiling heptane-insoluble component (i) in an amount of 50 to95% by weight, preferably 70 to 93% by weight, particularly preferably75 to 90% by weight.

[0568] This boiling heptane-insoluble component (i) essentially consistsof units derived from propylene, but in some cases, it contains unitsderived from other olefins than propylene which are used in thepreparation of the polypropylene component and a part of theethylene/α-olefin copolymer component. For example, the boilingheptane-insoluble component of the propylene block copolymer may containthe units derived from other olefin than propylene in an amount of notmore than 5% by mol, preferably not more than 4% by mol.

[0569] The boiling heptane-insoluble component of the propylene blockcopolymer obtained by the invention desirably has the followingproperties.

[0570] (i-1) The boiling heptane-insoluble component has a pentadisotacticity [M₅] of not less than 0.97, preferably 0.970 to 0.995, morepreferably 0.980 to 0.995, particularly preferably 0.982 to 0.995.

[0571] (i-2) The boiling heptane-insoluble component has a pentadtacticity [M₃] of 0.0020 to 0.0050, preferably 0.0023 to 0.0045, morepreferably 0.0025 to 0.0040.

[0572] (i-3) The boiling heptane-insoluble component of the propyleneblock copolymer obtained by the invention has a crystallinity, asmeasured by X-ray diffractometry, of usually not less than 60%,preferably not less than 65%, more preferably 65 to 95%, particularlypreferably 65 to 90%.

[0573] The pentad isotacticity [M₅] and the pentad tacticity [M₃] of thepropylene block copolymer can be determined in the same manner asdescribed before with respect to the pentad isotacticity [M₅] and thepentad tacticity [M₃] of the homopolypropylene.

[0574] The boiling heptane-insoluble component of the propylene blockcopolymer obtained by the invention is highly isotactic.

[0575] (ii-1) The propylene block copolymer obtained by the inventiondesirably contains a 24° C. n-decane-soluble component in an amount of60 to 3% by weight, preferably 50 to 3% by weight, more preferably 40 to3% by weight, particularly preferably 30 to 3% by weight.

[0576] (ii-2) The 23° C. n-decane-soluble component desirably has anintrinsic viscosity [η], as measured in decahydronaphthalene at 135° C.,of not less than 2 dl/g when the copolymer is prepared using thecatalyst (1), (1 a), (2) or (2 a); and of not less than 4 dl/g when thecopolymer is prepared using the catalyst (3), (3 a), (4), (4 a) or (5a); preferably 4 to 20 dl/g, more preferably 5 to 15 dl/g, particularlypreferably 6 to 12 dl/g.

[0577] Thus, the propylene block copolymer has a higher intrinsicviscosity [η] of 23° C. n-decane-soluble component as compared withthose prepared by the use of the conventional catalysts.

[0578] (ii-3) The 23° C. n-decane-soluble component of the propyleneblock copolymer desirably contains units derived from ethylene in anamount of 30 to 60% by mol, preferably 35 to 50% by mol.

[0579] In this specification, the amount of the 23° C. n-decane-solublecomponent (rubber component) contained in the propylene polymer isdetermined as follows.

[0580] A 1-liter flask equipped with a stirrer is charged with 3 g of apolymer sample, 20 mg of 2,6-di-tert-butyl-4-methylphenol and 500 ml ofn-decane, and heated at 145° C. in an oil bath to dissolve the polymersample. After the polymer sample is dissolved, the resulting solution iscooled to room temperature over a period of about 8 hours, followed bykeeping it for 8 hours in a water bath of 23° C. so as to precipitate apolymer. The resulting n-decane solution containing the precipitatedpolymer and the dissolved polymer is separated by filtration through aglass filter of G-4 (or G-2). The resulting solution is dried at 150° C.and 10 mmHg until the weight becomes unvaried, and the weight ismeasured. The weight thus measured is the weight of the polymer which issoluble in the above-mentioned mixed solvent, and a percentage of theweight to the weight of the sample polymer is calculated.

[0581] As described above, it is desired that the propylene blockcopolymer obtained by the invention contains a highly isotactic boilingheptane-insoluble component (i) and a 23° C. n-decane-soluble component(ii) having a high intrinsic viscosity [η].

[0582] In the case where the propylene block copolymer is prepared bythe use of the prepolymerized catalyst, it is desired that theprepolymer formed by the prepolymerization is contained in the propyleneblock copolymer in an amount of 0.001 to 3% by weight, preferably 0.005to 2% by weight.

[0583] The propylene block copolymer obtained by the invention desirablyhas a melt flow rate (MFR, as measured in accordance with ASTM D-1238 at230° C. under a load of 2.16 kg) of 0.01 to 500 g/10 min, preferably0.05 to 300 g/10 min, more preferably 0.08 to 200 g/10 min.

[0584] The propylene block copolymer obtained by the invention may beused, if desired, in combination with various additives such asnucleating agent, rubber ingredient, heat stabilizer, weatheringstabilizer, antistatic agent, anti-slip agent, anti-blocking agent,anti-fogging agent, lubricant, dye, pigment, natural oil, synthetic oil,wax and filler.

EFFECT OF THE INVENTION

[0585] By the use of the novel olefin polymerization catalysts accordingto the invention, extremely highly isotactic homopolypropylene can beprepared using a small amount of hydrogen in the preparation thereof ascompared with polymerization systems using the conventional catalysts.

[0586] The processes for preparing a propylene block copolymer using thenovel olefin polymerization catalysts and other processes according tothe invention, provide a propylene block copolymer containing anextremely highly isotactic polypropylene component and a high molecularweight rubber component.

EXAMPLE

[0587] The present invention is further described with reference to thefollowing examples, but it should be construed that the invention is inno way limited to those examples.

[0588] Physical properties of the polymers prepared in the followingexamples were measured by the methods described below.

Measurement of Physical Properties

[0589] 100 Parts by weight of the polymer obtained in each of Exampleswas mixed with 0.05 part by weight oftetrakis[methylene(3,5-di-t-butyl-4-hydroxy)hydrocinnamate]methane, 0.05part by weight of tris(mixed mono- and dinonylphenylphosphite) and 0.1part by weight of calcium stearate, and the mixture was granulated at250° C. by an extrusion granulator having a screw diameter of 20 mm(produced by Thermo Plastic Co.).

[0590] The granulate thus obtained is molded at 200° C. into ASTMstandard specimens for the following tests using an injection moldingmachine (produced by Toshiba Machine Co., Ltd.). The specimens weremeasured on flexural modulus (FM), heat distortion temperature (HDT) andIzod impact strength (IZ) in accordance with the ASTM standard measuringmethods. PS Flexural Modulus (FM):

[0591] The flexural modulus was measured in accordance with ASTM D-790.

[0592] Specimen: 12.7 cm×12.7 mm×3.0 mm

[0593] Heat Distortion Temperature (HDT):

[0594] The heat distortion temperature was measured in accordance withASTM D-648.

[0595] Specimen: 12.7 cm×12.7 mm×6.0 mm

Izod Impact Strength (IZ):

[0596] The Izod impact strength was measured in accordance with ASTMD-256.

[0597] Specimen: 12.7 cm×12.7 mm×6.0 mm, (notched)

EXAMPLE 1 Preparation of Homopolypropylene

[0598] [Preparation of Solid Titanium Catalyst Component (A)]

[0599] A mixture of 95.2 g of anhydrous magnesium chloride, 442 ml ofdecane and 390.6 g of 2-ethylhexyl alcohol was reacted under heating at130° C. for 2 hours to give a homogeneous solution. To the solution wasadded 21.3 g of phthalic anhydride, and the mixture was stirred at 130°C. for 1 hour to dissolve the phthalic anhydride.

[0600] After the resulting homogeneous solution was cooled to roomtemperature, 75 ml of this solution was dropwise added to 200 ml oftitanium tetrachloride kept at −20° C. over a period of 1 hour. Afterthe addition was completed, the temperature of the resulting mixture waselevated to 110° C. over a period of 4 hours. When the temperaturereached 110° C., 5.22 g of diisobutyl phthalate (DIBP) was added to thesolution, followed by stirring at the same temperature for 2 hours.

[0601] After the end of the 2-hour reaction, the mixture was hotfiltered to separate a solid which was resuspended in 275 ml of titaniumtetrachloride, and the resulting suspension was heated at 110° C. for 2hours.

[0602] After the end of the reaction, the mixture was hot filtered toseparate a solid which was thoroughly washed with decane and hexane at110° C. until any titanium compound liberating in the filtrate was notdetected.

[0603] The solid titanium catalyst component (A) prepared as above wasstored in the form of a slurry in decane, but a part thereof was driedfor the purpose of examining the catalyst composition.

[0604] The solid titanium catalyst component (A) thus obtained had acomposition comprising 2.3% by weight of titanium, 61% by weight ofchlorine, 19% by weight of magnesium and 12.5% by weight of DIBP.

[0605] [Preparation of Prepolymerized Catalyst [I]]

[0606] A 400 ml four-necked glass reactor equipped with a stirrer wascharged with 100 ml of purified hexane, 10 mmol of triethylaluminum, 2.0mmol of dicyclopentyldimethoxysilane (DCPMS) and 1.0 mmol (in terms oftitanium atom) of the solid titanium catalyst component (A) obtainedabove in a nitrogen atmosphere. Then, propylene was fed to the reactorat a rate of 3.2 1/hr for 1 hour, The polymerization temperature waskept at 20° C.

[0607] After the end of the propylene feeding, the reactor was purgedwith nitrogen, and washing operation consisting of removal of asupernatant and addition of purified hexane was carried out twice, toobtain a prepolymerized catalyst [I], which was resuspended in purifiedhexane, and the whole suspension was stored in a catalyst bottle.

[0608] [Polymerization]

[0609] Into a 17-liter autoclave were introduced 3 kg of propylene and45 liters of hydrogen, and the temperature of the system was raised to60° C. Then, 15 mmol of triethylaluminum, 15 mmol of2-isopentyl-2-isopropyl-1,3-dimethoxypropane (IPAMP) and 0.05 mmol (interms of titanium atom) of the prepolymerized catalyst [I] were added tothe autoclave. The temperature of the system was raised to 70° C., andthe same temperature was kept for 40 minutes to performhomopolymerization of propylene.

[0610] The results are shown in Table 1.

EXAMPLE 2

[0611] Preparation of Homopolypropylene

[0612] [Polymerization]

[0613] Into a 17-liter autoclave were introduced 3 kg of propylene and20 liters of hydrogen, and the temperature of the system was raised to60° C. Then, 15 mmol of triethylaluminum, 15 mmol of IPAMP and 0.05 mmol(in terms of titanium atom) of the prepolymerized catalyst [I] obtainedin Example 1 were added to the autoclave. The temperature of the systemwas raised to 70° C., and the same temperature was kept for 50 minutesto perform homopolymerization of propylene.

[0614] The results are shown in Table 1.

EXAMPLE 3 Preparation of Homopolypropylene

[0615] [Polymerization]

[0616] Homopolymerization of propylene was carried out in the samemanner as in Example 2 except that hydrogen was added in an amount of 8liters.

[0617] The results are shown in Table 1.

EXAMPLE 4 Preparation of Propylene Block Copolymer

[0618] [Polymerization]

[0619] Into a 17-liter autoclave were introduced 3 kg of propylene and50 liters of hydrogen, and the temperature of the system was raised to60° C. Then, 15 mmol of triethylaluminum, 15 mmol of IPAMP and 0.05 mmol(in terms of titanium atom) of the prepolymerized catalyst [I] obtainedin Example 1 were added to the autoclave. The temperature of the systemwas raised to 70° C., and the same temperature was kept for 40 minutesto perform homopolymerization of propylene.

[0620] After the end of the homopolymerization of propylene, the ventvalve was opened to release the autoclave until the pressure reachedatmospheric pressure.

[0621] After the end of the release of pressure, copolymerization ofethylene and propylene was carried out in the following manner. Ethyleneand propylene were fed to the polymerization reactor at rates of 240Nl/hr and 960 Nl/hr, respectively. The vent was adjusted on its openingdegree so that the pressure in the reactor became 10 kg/cm²-G. Thepolymerization was carried out for 80 minutes with keeping thetemperature at 70° C. To the reaction system was added a small amount ofethanol to terminate the polymerization reaction, and the unreacted gaswas purged out from the reactor.

[0622] The results are shown in Table 1.

EXAMPLE 5 Preparation of Propylene Block Copolymer

[0623] [Polymerization]

[0624] Polymerization was carried out in the same manner as in Example 4except that in the copolymerization of ethylene and propylene, ethyleneand propylene were fed at rates of 450 Nl/hr and 750 Nl/hr,respectively.

[0625] The results are shown in Table 1.

EXAMPLE 6 Preparation of Propylene Block Copolymer

[0626] [Polymerization]

[0627] Polymerization was carried out in the same manner as in Example 4except that hydrogen was added in an amount of 20 liters in thehomopolymerization of propylene and the homopolymerization time waschanged to 50 minutes.

[0628] The results are shown in Table 1.

EXAMPLE 7 Preparation of Propylene Block Copolymer

[0629] [Polymerization]

[0630] Polymerization was carried out in the same manner as in Example 5except that hydrogen was added in an amount of 8 liters in thehomopolymerization of propylene and the homopolymerization time waschanged to 50 minutes.

[0631] The results are shown in Table 1.

COMPARATIVE EXAMPLE 1

[0632] [Preparation of Prepolymerized Catalyst [Iref]]

[0633] A 400 ml four-necked glass reactor equipped with a stirrer wascharged with 100 ml of purified hexane, 3.0 mmol of triethylaluminum and1.0 mmol (in terms of titanium atom) of the solid titanium catalystcomponent (A) obtained in Example 1 in a nitrogen atmosphere. Then,propylene was was fed to the reactor at a rate of 3.2 1/hr for 1 hour.The polymerization temperature was kept at 20° C.

[0634] After the end of the propylene feeding, the reactor was purgedwith nitrogen, and washing operation consisting of removal of asupernatant and addition of purified hexane was carried out twice, toobtain a prepolymerized catalyst [I_(ref)], which was resuspended inpurified hexane, and the whole suspension was transferred into acatalyst bottle.

[0635] [Polymerization]

[0636] Into a 17-liter autoclave were introduced 3 kg of propylene and40 liters of hydrogen, and the temperature of the system was raised to60° C. Then, 15 mmol of triethylaluminum, 5 mmol ofdiphenyldimethoxysilane (DPMS) and 0.05 mmol (in terms of titanium atom)of the prepolymerized catalyst [I_(ref)] were added to the autoclave.The temperature of the system was raised to 70° C., and the sametemperature was kept for 25 minutes to perform homopolymerization ofpropylene.

[0637] After the end of the homopolymerization of propylene, the ventvalve was opened to release the autoclave until the pressure reachedatmospheric pressure.

[0638] After the release of pressure, copolymerization of ethylene andpropylene was carried out in the following manner. Ethylene, propyleneand hydrogen were fed to the polymerization reactor at rates of 240Nl/hr, 960 Nl/hr and 5 Nl/hr, respectively. The vent of the reactor wasadjusted on its opening degree so that the pressure in the reactorbecame 10 kg/cm²-G. The polymerization was carried out for 50 minuteswith keeping the temperature at 70° C. To the reaction system was addeda small amount of ethanol to terminate the polymerization reaction, andthe unreacted gas was purged out from the reactor to obtain a whitepowder, which was dried at 80° C. under reduced pressure.

[0639] The results are shown in Table 1.

COMPARATIVE EXAMPLE 2

[0640] Polymerization was carried out in the same manner as inComparative Example 1 except that the copolymerization of ethylene andpropylene was performed for 40 minutes.

[0641] The results are shown in Table 1.

COMPARATIVE EXAMPLE 3

[0642] [Polymerization]

[0643] Into a 17-liter autoclave were introduced 3 kg of propylene and45 liters of hydrogen, and the temperature of the system was raised to60° C. Then, 15 mmol of triethylaluminum, 5 mmol of DPMS and 0.05 mmol(in terms of titanium atom) of the prepolymerized catalyst [I_(ref)]were added to the autoclave. The temperature of the system was raised to70° C., and the same temperature was kept for 25 minutes to performhomopolymerization of propylene.

[0644] After the end of the homopolymerization of propylene, the ventvalve was opened to release the autoclave until the pressure reachedatmospheric pressure.

[0645] After the release of pressure, copolymerization of ethylene andpropylene was carried out in the following manner. Ethylene andpropylene were fed to the polymerization reactor at rates of 240 Nl/hrand 960 Nl/hr, respectively. The vent of the reactor was adjusted on itsopening degree so that the pressure in the reactor became 10 kg/cm²-G.The polymerization was carried out for 50 minutes with keeping thetemperature at 70° C. To the reaction system was added a small amount ofethanol to terminate the polymerization reaction, and the unreacted gaswas purged out from the reactor to obtain a white powder, which wasdried at 80° C. under reduced pressure.

[0646] The results are shown in Table 1.

COMPARATIVE EXAMPLE 4

[0647] Polymerization was carried out in the same manner as inComparative Example 3 except that the copolymerization of ethylene andpropylene was performed for 40 minutes.

[0648] The results are shown in Table 1.

COMPARATIVE EXAMPLE 5

[0649] Polymerization was carried out in the same manner as inComparative Example 1 except that the copolymerization of ethylene andpropylene was not performed.

[0650] The results are shown in Table 1. TABLE 1 23° C. n-Decane- Bulksoluble component specific Ethylene Activity MFR gravity Content content[η] No. g/mol-Ti g/10 min g/ml wt % mol % dl/g Ex. 1 30,200 105 0.46 0.7— — Ex. 2 31,900 51 0.47 0.6 — — Ex. 3 31.100 25 0.47 0.6 — — Ex. 436,200 48 0.46 8.9 40.2 6.8 Ex. 5 36,700 45 0.45 10.2 46.2 7.2 Ex. 637,400 24 0.46 9.1 36.2 6.8 Ex. 7 36,400 9 0.45 9.5 38.2 7.0 Comp.51,500 46 0.43 12.0 40.5 2.2 Ex. 1 Comp. 47,600 50 0.43 8.7 38.8 2.1 Ex.2 Comp. 50,000 43 0.43 10.6 39.4 4.8 Ex. 3 Comp. 47,200 46 0.43 8.3 38.64.5 Ex. 4 Comp. 40,000 96 0.46 2.2 — — Ex. 5 23° C. n-Decane-insolublecomponent Boiling heptane- Ethylene insoluble component IZ contentContent [M₅] [M₃] FM HDT kg · No. mol % wt % (%) (%) kg/cm² ° C. cm/cmEx. 1 — 96.0 98.9 0.25 — — — Ex. 2 — 96.4 98.3 0.27 — — — Ex. 3 — 96.998.3 0.25 — — — Ex. 4 0.8 94.4 98.8 0.32 17,100 118 7.0 Ex. 5 1.2 94.398.6 0.31 16,600 115 7.6 Ex. 6 0.8 94.7 98.8 0.28 16,300 115 7.7 Ex. 70.9 94.9 98.8 0.30 16,000 114 8.0 Comp. 2.4 89.8 96.2 0.35 14,000 1083.5 Ex. 2 Comp. 2.2 89.6 96.2 0.35 14,300 110 2.7 Ex. 2 Comp. 2.7 89.696.2 0.37 14,600 110 4.8 Ex. 3 Comp. 2.5 89.7 96.7 0.34 14,900 111 4.3Ex. 4 Comp. — 90.5 96.8 0.27 — — —

EXAMPLE 8 Preparation of Propylene Block Copolymer

[0651] [Preparation of Prepolymerized Catalyst [1-2]]

[0652] A 400 ml four-necked glass reactor equipped with a stirrer wascharged with 100 ml of purified hexane, 10 mmol of triethylaluminum, 2.0mmol of 2-isopentyl-2-isopropyl-1,3-dimethoxypropane (IPAMP) and 1.0mmol (in terms of titanium atom) of the solid titanium catalystcomponent (A) obtained as above in a nitrogen atmosphere. Then,propylene was fed to the reactor at a rate of 3.2 1/hr for 1 hour. Thepolymerization temperature was kept at 20° C.

[0653] After the end of propylene feeding, the reactor was purged withnitrogen, and washing operation consisting of removal of a supernatantand addition of purified hexane was carried out twice, to obtain aprepolymerized catalyst [I-2], which was resuspended in purified hexane,and the whole suspension was stored in a catalyst bottle.

[0654] [Polymerization]

[0655] Into a 17-liter autoclave were introduced 3 kg of propylene and50 liters of hydrogen, and the temperature of the system was raised to60° C. Then, 15 mmol of triethylaluminum, 15 mmol ofdicyclopentyldimethoxysilane (DCPMS) and 0.05 mmol (in terms of titaniumatom) of the prepolymerized catalyst [I-2] were added to the autoclave.The temperature of the system was raised to 70° C., and the sametemperature was kept for 40 minutes to perform homopolymerization ofpropylene.

[0656] After the end of the homopolymerization, the vent valve wasopened to release the autoclave until the pressure reached atmosphericpressure.

[0657] After the release of pressure, copolymerization of ethylene andpropylene was carried out in the following manner. Ethylene andpropylene were fed to the polymeriation reactor at rates of 240 Nl/hrand 960 Nl/hr, respectively. The vent of the reactor was adjusted on itsopening degree so that the pressure in the polymerizer became 10kg/cm²-G. The polymerization was carried out for 80 minutes with keepingthe temperature at 70° C. To the reaction system was added a smallamount of ethanol to terminate the polymerization reaction, and theunreacted gas was purged out from the reactor.

[0658] The results are shown in Table 2.

EXAMPLE 9 Preparation of Propylene Block Copolymer

[0659] Polymerization was carried out in the same manner as in Example 8except that in the copolymerization of ethylene and propylene, ethyleneand propylene were fed at rates of 450 Nl/hr and 750 NI/hr,respectively.

[0660] The results are shown in Table 2.

EXAMPLE 10 Preparation of Propylene Block Copolymer

[0661] Polymerization was carried out in the same manner as in Example 8except that hydrogen was added in an amount of 20 liters in thehomopolymerization of propylene and the homopolymerization time waschanged to 50 minutes.

[0662] The results are shown in Table 2.

EXAMPLE 11 Preparation of Propylene Block Copolymer

[0663] Polymerization was carried out in the same manner as in Example 8except that hydrogen was added in an amount of 8 liters in thehomopolymerization of propylene and the homopolymerization time waschanged to 50 minutes.

[0664] The results are shown in Table 2. TABLE 2 23° C. n-Decane- Bulksoluble component specific Ethylene Activity MFR gravity Content content[η] No. g/mol-Ti g/10 min g/ml wt % mol % dl/g Ex. 8  34,700 50 0.45 8.440.1 6.6 Ex. 9  35,100 48 0.44 10.0 46.2 7.0 Ex. 10 34,700 27 0.46 8.537.0 6.8 Ex. 11 35,000 11 0.44 8.9 40.3 7.0 23° C. n-Decane-insolublecomponent Boiling heptane- Ethylene insoluble component IZ contentContent [M₅] [M₃] FM HDT kg · No. mol % wt % (%) (%) kg/cm² ° C. cm/cmEx. 8  0.8 94.5 99.0 0.27 17,000 117 7.2 Ex. 9  1.4 94.2 99.1 0.3116,700 115 7.5 Ex. 10 0.8 94.8 99.1 0.30 16,500 117 7.8 Ex. 11 1.0 94.999.1 0.29 16,400 116 7.9

EXAMPLE 12 Preparation of Propylene Block Copolymer

[0665] [Polymerization]

[0666] Into a 17-liter autoclave were introduced 3 kg of propylene and40 liters of hydrogen, and the temperature of the system was raised to60° C. Then, 15 mmol of triethylaluminum, 15 mmol of IPAMP and 0.05 mmol(in terms of titanium atom) of the prepolymerized catalyst [I-2] wereadded to the autoclave. The temperature of the system was raised to 70°C., and the same temperature was kept for 40 minutes to performhomopolymerization of propylene.

[0667] After the end of the homopolymerization of propylene, the ventvalve was opened to release the autoclave until the pressure reachedatmospheric pressure.

[0668] After the release of pressure, copolymerization of ethylene andpropylene was carried out in the following manner. Ethylene andpropylene were fed to the polymerization reactor at rates of 240 Nl/hrand 960 Nl/hr, respectively. The vent of the reactor was adjusted on itsopening degree so that the pressure in the reactor became 10 kg/cm²-G.The polymerization was carried out for 80 minutes with keeping thetemperature at 70° C. To the reaction system was added a small amount ofethanol to terminate the polymerization reaction, and the unreacted gaswas purged out from the reactor.

[0669] The results are shown in Table 3.

EXAMPLE 13 Preparation of Propylene Block Copolymer

[0670] Polymerization was carried out in the same manner as in Example12 except that in the copolymerization of ethylene and propylene,ethylene and propylene were fed to the polymerization reactor at ratesof 450 Nl/hr and 750 Nl/hr, respectively.

[0671] The results are shown in Table 3.

EXAMPLE 14 Preparation of Propylene Block Copolymer

[0672] Polymerization was carried out in the same manner as in Example12 except that hydrogen was added in an amount of 17 liters in thehomopolymerization of propylene and the homopolymerization time waschanged to 50 minutes.

[0673] The results are shown in Table 3.

EXAMPLE 15 Preparation of Propylene Block Copolymer

[0674] Polymerization was carried out in the same manner as in Example12 except that hydrogen is added in an amount of 7 liters in thehomopolymerization of propylene and the homopolymerization time waschanged to 50 minutes.

[0675] The results are shown in Table 3. TABLE 3 23° C. n-Decane- Bulksoluble component specific Ethylene Activity MFR gravity Content content[η] No. g/mol-Ti g/10 min g/ml wt % mol % dl/g Ex. 12 35,200 49 0.45 8.139.5 6.7 Ex. 13 36,200 45 0.45 10.3 45.8 7.0 Ex. 14 35,300 25 0.47 9.036.8 6.8 Ex. 15 36,200 13 0.45 9.3 40.0 7.1 23° C. n-Decane-insolublecomponent Boiling heptane- Ethylene insoluble component IZ contentContent [M₅] [M₃] FM HDT kg · No. mol % wt % (%) (%) kg/cm² ° C. cm/cmEx. 12 0.9 94.4 98.8 0.27 17,100 117 7.0 Ex. 13 1.2 94.3 98.6 0.3316,500 116 7.6 Ex. 14 0.9 94.6 98.6 0.29 16,200 115 7.7 Ex. 15 0.9 94.998.8 0.29 16,200 115 8.0

EXAMPLE 16 Preparation of Propylene Block Copolymer

[0676] [Preparation of Solid Titanium Catalyst Component (A-2)]

[0677] A mixture of 95.2 g of anhydrous magnesium chloride, 442 ml ofdecane and 390.6 g of 2-ethylhexyl alcohol was reacted under heating at130° C. for 2 hours to give a homogeneous solution. To the solution wasadded 21.3 g of phthalic anhydride, and the mixture was stirred at 130°C. for 1 hour to dissolve the phthalic anhydride in the solution.

[0678] After the resulting homogeneous solution was cooled to roomtemperature, 75 ml of this solution was dropwise added to 200 ml oftitanium tetrachloride kept at −20° C. over a period of 1 hour. Afterthe addition was completed, the temperature of the resulting mixture waselevated to 110° C. over a period of 4 hours. When the temperaturereached 110° C., 4.79 ml of 2-isopropyl-2-isopentyl-1,3-dimethoxysilane(IPAMP) was added to the solution, followed by stirring at the sametemperature for 2 hours.

[0679] After the end of the 2-hour reaction, the mixture was hotfiltered to separate a solid which was resuspended in 275 ml of titaniumtetrachloride, and the resulting suspension was heated at 110° C. for 2hours.

[0680] After the end of the reaction, the mixture was hot filtered toseparate a solid which was thoroughly washed with decane and hexane at110° C. until any titanium compound liberating in the filtrate was notdetected.

[0681] The solid titanium catalyst component (A-2) prepared as above wasstored in the form of a slurry in decane, but a part thereof was driedfor the purpose of examining the catalyst composition.

[0682] The solid titanium catalyst component (A-2) thus obtained had acomposition comprising 2.3% by weight of titanium, 62% by weight ofchlorine, 22% by weight of magnesium and 9.2% by weight of IPAMP.

[0683] Preparation of Prepolymerized Catalyst [I-4]

[0684] A 400 ml four-necked glass reactor equipped with a stirrer wascharged with 100 ml of purified hexane, 3 mmol of triethylaluminum and1.0 mmol (in terms of titanium atom) of the solid titanium catalystcomponent (A-2) obtained as above in a nitrogen atmosphere. Then,propylene was fed to the reactor at a rate of 3.2 1/hr for 1 hour. Thepolymerization temperature was kept at 20° C.

[0685] After the end of propylene feeding, the reactor was purged withnitrogen, and washing operation consisting of removal of a supernatantand addition of purified hexane was carried out twice, to obtain aprepolymerized catalyst [I-4], which was resuspended in purified hexane,and the whole suspension was stored in a catalyst bottle.

[0686] [Polymerization]

[0687] Into a 17-liter autoclave were introduced 3 kg of propylene and50 liters of hydrogen, and the temperature of the system was raised to60° C. Then, 15 mmol of triethylaluminum, 15 mmol of2-isopentyl-2-isopropyl-1,3-dimethoxypropane (IPAMP) and 0.03 mmol (interms of titanium atom) of the prepolymerized catalyst [I-4] were addedto the autoclave. The temperature of the system was raised to 70° C.,and the same temperature was kept for 40 minutes to performhomopolymerization of propylene.

[0688] After the end of the homopolymerization of propylene, the ventvalve was opened to release the autoclave until the pressure reachedatmospheric pressure.

[0689] After the release of pressure, copolymerization of ethylene andpropylene was carried out in the follwoing manner. Ethylene andpropylene were fed to the polymerization reactor at rates of 240 Nl/hrand 960 Nl/hr, respectively. The vent of the polymerizer was adjusted onits opening degree so that the pressure in the reactor became 10kg/cm²-G. The polymerization was carried out for 80 minutes with keepingthe temperature at 70° C. To the reaction system was added a smallamount of ethanol to terminate the polymerization reaction, and theunreacted gas was purged out from the reactor.

[0690] The results are shown in Table 4.

EXAMPLE 17 Preparation of Propylene Block Copolymer

[0691] Polymerization was carried out in the same manner as in Example16 except that dicyclopentyldimethoxysilane (DCPMS) was used in place ofIPAMP.

[0692] The results are shown in Table 4.

EXAMPLE 18 Preparation of Propylene Block Copolymer

[0693] Polymerization was carried out in the same manner as in Example16 except that in the copolymerization of ethylene and propylene,ethylene and propylene were fed to the polymerization reactor at ratesof 450 Nl/hr and 750 Nl/hr, respectively.

[0694] The results are shown in Table 4.

EXAMPLE 19 Preparation of Propylene Block Copolymer

[0695] Polymerization was carried out in the same manner as in Example16 except that hydrogen was added in an amount of 20 liters in thehomopolymerization of propylene and the homopolymerization time waschanged to 50 minutes.

[0696] The results are shown in Table 4.

EXAMPLE 20 Preparation of Propylene Block Copolymer

[0697] Polymerization was carried out in the same manner as in Example16 except that hydrogen was added in an amount of 8 liters in thehomopolymerization of propylene and the homopolymerization time waschanged to 50 minutes.

[0698] The results are shown in Table 4. TABLE 4 23° C. n-Decane- Bulksoluble component specific Ethylene Activity MFR gravity Content content[η] No. g/mol-Ti g/10 min g/ml wt % mol % dl/g Ex. 16 77,600 44 0.46 8.338.2 6.7 Ex. 17 77,200 40 0.47 8.0 37.6 6.9 Ex. 18 80,200 43 0.45 10.245.2 7.4 Ex. 19 72,400 22 0.46 8.8 38.0 6.7 Ex. 20 70,000 10 0.45 8.439.6 7.0 23° C. n-Decane-insoluble component Boiling heptane- Ethyleneinsoluble component IZ content Content [M₅] [M₃] FM HDT kg · No. mol %wt % (%) (%) kg/cm² ° C. cm/cm Ex. 16 0.9 94.2 98.6 0.32 16,900 117 6.9Ex. 17 1.0 94.0 98.9 0.31 17,200 119 6.7 Ex. 18 1.4 94.1 98.6 0.3116,500 116 7.5 Ex. 19 0.8 94.6 98.6 0.30 16,000 114 7.6 Ex. 20 1.0 94.998.6 0.30 16,000 114 7.8

EXAMPLE 21 Preparation of Propylene Block Copolymer

[0699] [Polymerization]

[0700] Into a 17-liter autoclave were introduced 3 kg of propylene and120 liters of hydrogen, and the temperature of the system was raised to60° C. Then, 15 mmol of triethylaluminum, 15 mmol ofdicyclopentyldimethoxysilane (DCPMS) and 0.05 mmol (in terms of titaniumatom) of the prepolymerized catalyst [I] were added to the autoclave.The temperature of the system was raised to 70° C., and the sametemperature was kept for 35 minutes to perform homopolymerization ofpropylene.

[0701] After the end of the homopolymerization of propylene, the ventvalve was opened to release the autoclave until the pressure reachedatmospheric pressure.

[0702] After the release of pressure, copolymerization of ethylene andpropylene was carried out in the following manner. Ethylene andpropylene were fed to the polymerization reactor at rates of 240 Nl/hrand 960 Nl/hr, respectively. The vent of the polymerizer was adjusted onits opening degree so that the pressure in the reactor became 10kg/cm²-G. The polymerization was carried out for 80 minutes with keepingthe temperature at 70° C. To the reaction system was added a smallamount of ethanol to terminate the polymerization reaction, and theunreacted gas was purged out from the reactor.

[0703] The results are shown in Table 5.

EXAMPLE 22 Preparation of Propylene Block Copolymer

[0704] Polymerization was carried out in the same manner as in Example21 except that in the copolymerization of ethylene and propylene,ethylene and propylene were fed to the polymerization reactor at ratesof 480 Nl/hr and 720 Nl/hr, respectively.

[0705] The results are shown in Table 5.

EXAMPLE 23 Preparation of Propylene Block Copolymer

[0706] Polymerization was carried out in the same manner as in Example21 except that hydrogen was added in an amount of 50 liters in thehomopolymerization of propylene and the homopolymerization time waschanged to 40 minutes.

[0707] The results are shown in Table 5.

EXAMPLE 24 Preparation of Propylene Block Copolymer

[0708] Polymerization was carried out in the same manner as in Example21 except that hydrogen is added in an amount of 20 liters in thehomopolymerization of propylene and the homopolymerization time waschanged to 40 minutes.

[0709] The results are shown in Table 5. TABLE 5 23° C. n-Decane- Bulksoluble component specific Ethylene Activity MFR gravity Content content[η] No. g/mol-Ti g/10 min g/ml wt % mol % dl/g Ex. 21 47,600 44 0.45 8.140.9 6.1 Ex. 22 49,400 46 0.45 9.0 45.0 6.8 Ex. 23 50,600 25 0.46 9.237.0 6.2 Ex. 24 51,100 13 0.45 8.5 39.2 6.6 23° C. n-Decane-insolublecomponent Boiling heptane- Ethylene insoluble component IZ contentContent [M₅] [M₃] FM HDT kg · No. mol % wt % (%) (%) kg/cm² ° C. cm/cmEx. 21 1.0 94.5 99.2 0.29 17,300 118 7.0 Ex. 22 1.4 94.7 99.0 0.3417,000 116 7.2 Ex. 23 0.8 95.0 99.0 0.30 16,800 116 7.5 Ex. 24 0.8 95.399.1 0.34 16,500 116 7.6

EXAMPLE 25

[0710] [Preparation of prepolymerized catalyst [I-5]]

[0711] Into a 400 ml glass reactor purged with nitrogen was introduced200 ml of purified hexane. Then, to the reactor were added 20 mmol oftriethylaluminum, 4 mmol of dicyclopentyldimethoxysilane (DCPMS) and 2mmol (in terms of titanium atom) of the solid titanium catalystcomponent (A) prepared in Example 1. Thereafter, propylene was fed tothe reactor at a rate of 7.3 Nl/hr for 1 hour to performprepolymerization. The amount of propylene prepolymerized was 3 g per 1g of the solid titanium catalyst component (A).

[0712] After the end of the prepolymerization, the mixture was filteredto separate a solid. The resulting solid, a prepolymerized catalyst[I-5], was resuspended in decane.

[0713] [Polymerization]

[0714] Into a 2-liter autoclave, 800 ml of purified decane wasintroduced and then 0.75 ml of triethylaluminum, 0.15 mmol ofdicyclopentyldimethoxysilane (DCPMS) and 0.015 mmol (in terms oftitanium atom) of the prepolymerized catalyst [I-5] as obtained abovewere further introduced at room temperature in a propylene atmosphere.After 1.8 Nl of hydrogen was fed to the autoclave, the temperature ofthe system was raised to 80° C. with feeding propylene. Thepolymerization pressure was kept at 7 kg/cm²-G by feeding propylene tothe autoclave.

[0715] After the polymerization of propylene was carried out for 30minutes, the system was cooled to 60° C. and the autoclave was released.Then, the unreacted propylene was purged out for 20 minutes withnitrogen.

[0716] The polypropylene component prepared by the above polymerizationcontained a 23° C. n-decane-soluble component in an amount of 1.0% byweight, and a 23° C. n-decane-insoluble component thereof had a pentadisotacticity [M₅] of 0.980.

[0717] Subsequently, 20 Nml of hydrogen was added at a time to thesystem in a nitrogen atmosphere. Then, a gas mixture composed of 68% bymol of propylene and 32% by mol of ethylene was introduced into thesystem to perform polymerization for 40 minutes under constantconditions of a temperature of 60° C. and a pressure of 5 kg/cm²-G.

[0718] After the end of the polymerization, the slurry containing thepolymer produced was filtered at 60° C. to remove a liquid portion,thereby obtaining a white powdery polymer which was washed twice with 1liter of hexane at room temperature.

[0719] An yield of the dry propylene block copolymer was 210 g, so thatthe activity of the catalyst was 14,000 g/mmol-Ti. This propylene blockcopolymer had an MFR of 2.2 g/10 min.

[0720] The propylene block copolymer contained 31% by weight of a 23° C.n-decane soluble component and 69% by weight of 23° C. n-decaneinsoluble component.

[0721] The 23° C. n-decane-soluble component had an ethylene content of37% by mel and an intrinsic viscosity [η] of 7.3 dl/g. The 23° C.n-decane-insoluble component had an MFR of 130 g/10 min and a pentadisotacticity [M₅] of 0.985.

EXAMPLE 26 Preparation of Propylene Block Copolymer

[0722] [Preparation of Precontact Product [Ib]]

[0723] A 400 ml four-necked glass reactor equipped with a stirrer wascharged with 100 ml of purified hexane, 10 mmol of triethylaluminum, 2.0mmol of dicyclopentyldimethoxysilane (DCPMS) and 1.0 mmol (in terms oftitanium atom) of the solid titanium catalyst component (A) obtained inExample 1 in a nitrogen atmosphere, and then the mixture was stirred at20° C. for 1 hour.

[0724] Thereafter, washing operation consisting of removal of asupernatant and addition of purified hexane was carried out twice, toobtain a precontact product [Ib], which was resuspended in purifiedhexane, and the whole suspension was stored in a catalyst bottle.

[0725] [Polymerization]

[0726] Into a 17-liter autoclave were introduced 3 kg of propylene and45 liters of hydrogen, and then at room temperature, 15 mmol oftriethylaluminum, 15 mmol of2-isopentyl-2-isopropyl-1,3-dimethoxypropane (IRAMP) and 0.05 mmol (interms of titanium atom) of the precontact product [Ib] were added to theautoclave. The temperature of the system was raised to 70° C., and thesame temperature was kept for 40 minutes to perform homopolymerizationof propylene.

[0727] After the end of the homopolymerization of propylene, the ventvalve was opened to release the autoclave until the pressure reachedatmospheric pressure.

[0728] After the end of the release of pressure, copolymerization ofethylene and propylene was carried out in the following manner. Ethyleneand propylene were fed to the polymerization reactor at rates of 240Nl/hr and 960 Nl/hr, respectively. The vent was adjusted on its openingdegree so that the pressure in the reactor became 10 kg/cm²-G. Thepolymerization was carried out for 80 minutes with keeping thetemperature at 70° C. To the reaction system was added a small amount ofethanol to terminate the polymerization reaction, and the unreacted gaswas purged out from the reactor. The resulting white powder was dried at80° C. under reduced pressure.

EXAMPLE 27 Preparation of Propylene Block Copolymer

[0729] [Preparation of Prepolymerized Catalyst [Ic]

[0730] A 400 ml four-necked glass reactor equipped with a stirrer wascharged with 100 ml of purified hexane, 10 mmol of triethylaluminum, 2.0mmol of di-t-butyldimethoxysilane (DTBMS) and 1.0 mmol (in terms oftitanium atom) of the solid titanium catalyst component (A) obtained inExample 1 in a nitrogen atmosphere. Then, propylene was fed to thereactor at a rate of 3.2 1/hr for 1 hour. The polymerization temperaturewas kept at 20° C.

[0731] After the end of the propylene feeding, the reactor was purgedwith nitrogen, and washing operation consisting of removal of asupernatant and addition of purified hexane was carried out twice, toobtain a prepolymerized catalyst [Ic], which was resuspended in purifiedhexane, and the whole suspension was stored in a catalyst bottle.

[0732] [Polymerization]

[0733] Into a 17-liter autoclave were introduced 3 kg of propylene and45 liters of hydrogen, and the temperature of the system was raised to60° C. Then, 15 mmol of triethylaluminum, 15 mmol of2-isopentyl-2-isopropyl-1,3-dimethoxypropane (IPAMP) and 0.05 mmol (interms of titanium atom) of the prepolymerized catalyst [Ic] were addedto the autoclave. The temperature of the system was raised to 70° C.,and the same temperature was kept for 40 minutes to performhomopolymerization of propylene.

[0734] After the end of the homopolymerization of propylene, the ventvalve was opened to release the autoclave until the pressure reachedatmospheric pressure.

[0735] After the end of the release of pressure, copolymerization ofethylene and propylene was carried out in the following manner. Ethyleneand propylene were fed to the polymerization reactor at rates of 240Nl/hr and 960 Nl/hr, respectively. The vent was adjusted on its openingdegree so that the pressure in the reactor became 10 kg/cm²-G. Thepolymerization was carried out for 50 minutes with keeping thetemperature at 70° C. To the reaction system was added a small amount ofethanol to terminate the polymerization reaction, and the unreacted gaswas purged out from the reactor. The resulting white powder was dried at80° C. under reduced pressure.

[0736] The results are shown in Table 6.

EXAMPLE 28 Preparation of Propylene Block Copolymer

[0737] [Preparation of Prepolymerized Catalyst [Id]]

[0738] Prepolymerization was carried out in the same manner as inExample 27 except that DCPMS is used in place of DTBMS, to obtain aprepolymerized catalyst [Id].

[0739] [Polymerization]

[0740] Polymerization was carried out in the same manner as in Example27 except that the prepolymerized catalyst [Id] was used in place of theprepolymerized catalyst [Ic], and2-isopropyl-2-isobutyl-1,3-dimethoxypropane was used in place of IPAMP.

[0741] The results are shown in Table 6. TABLE 6 23° C. n-Decane- Bulksoluble component specific Ethylene Activity MFR gravity Content content[η] No. g/mol-Ti g/10 min g/ml wt % mol % dl/g Ex. 26 35,000 54 0.43 9.638.9 6.2 Ex. 27 35,900 46 0.47 8.5 40.5 6.8 Ex. 28 35,200 51 0.47 9.339.4 6.5 23° C. n-Decane-insoluble component Boiling heptane- Ethyleneinsoluble component IZ content Content [M₅] [M₃] FM HDT kg · No. mol %wt % (%) (%) kg/cm² ° C. cm/cm Ex. 26 1.0 94.1 98.6 0.32 16,800 115 6.7Ex. 27 0.9 94.0 98.7 0.30 16,800 116 6.8 Ex. 28 0.8 94.7 98.1 0.3015,600 113 6.8

EXAMPLE 29 Preparation of Propylene Block Copolymer

[0742] [Preparation of Precontact Product [Ie]]

[0743] The procedures for the preparation of the precontact product [Ib]in Example 26 were repeated except that IPAMP was used in place ofDCPMS, to obtain a precontact product [Ie].

[0744] [Polymerization]

[0745] Polymerization was carried out in the same manner as in Example26 except that the precontact product [Ie] was used in place of theprecontact product [Ib], and DCPMS was used in place of IPAMP.

[0746] The results are shown in Table 7.

EXAMPLE 30 Preparation of Propylene Block Copolymer

[0747] [Preparation of Prepolymerized Catalyst [If]]

[0748] Prepolymerization was carried out in the same manner as inExample 27 except that IPAMP was used in place of DCPMS, to obtain aprepolymerized catalyst [If].

[0749] [Polymerization]

[0750] Polymerization was carried out in the same manner as in Example27 except that the prepolymerized catalyst [If] was used in place of theprepolymerized catalyst [Ic], and DTBMS was used in place of IPAMP.

[0751] The results are shown in Table 7.

EXAMPLE 31 Preparation of Propylene Block Copolymer

[0752] [Preparation of Prepolymerized Catalyst [Ig]]

[0753] Prepolymerization was carried out in the same manner as inExample 27 except that 2-isopropyl-2-isobutyl-1,3-dimethoxypropane wasused in place of DCPMS, to obtain a prepolymerized catalyst [Ig].

[0754] [Polymerization]

[0755] Polymerization was carried out in the same manner as in Example27 except that the prepolymerized catalyst [Ig] was used in place of theprepolymerized catalyst [Ic], and DCPMS was used in place of IPAMP.

[0756] The results are shown in Table 7. TABLE 7 23° C. n-Decane- Bulksoluble component specific Ethylene Activity MFR gravity Content content[η] No. g/mol-Ti g/10 min g/ml wt % mol % dl/g Ex. 29 33,800 55 0.43 8.939.4 6.4 Ex. 30 34,800 48 0.45 8.0 40.7 6.6 Ex. 31 35,200 47 0.45 8.740.5 6.8 23° C. n-Decane-insoluble component Boiling heptane- Ethyleneinsoluble component IZ content Content [M₅] [M₃] FM HDT kg · No. mol %wt % (%) (%) kg/cm² ° C. cm/cm Ex. 29 0.7 94.1 98.8 0.30 16,500 116 6.9Ex. 30 0.9 94.3 98.8 0.30 16,900 117 6.4 Ex. 31 0.7 94.5 98.1 0.3215,700 113 7.0

EXAMPLE 32 Preparation of Propylene Block Copolymer

[0757] [Polymerization]

[0758] Polymerization was carried out in the same manner as in Example26 except that the precontact product [Ie] was used in place of theprecontact product [Ib].

[0759] The results are shown in Table 8.

EXAMPLE 33 Preparation of Propylene Block Copolymer

[0760] [Polymerization]

[0761] Polymerization was carried out in the same manner as in Example27 except that the prepolymerized catalyst [Ig] was used in place of theprepolymerized catalyst [Ic], and2-isopropyl-2-isobutyl-1,3-dimethoxysilane was used in place of IPAMP.

[0762] The results are shown in Table 8. TABLE 8 23° C. n-Decane- Bulksoluble component specific Ethylene Activity MFR gravity Content content[η] No. g/mol-Ti g/10 min g/ml wt % mol % dl/g Ex. 32 34,500 55 0.43 8.637.4 6.5 Ex. 33 35,400 48 0.46 8.4 40.3 6.2 23° C. n-Decane-insolublecomponent Boiling heptane- Ethylene insoluble component IZ contentContent [M₅] [M₃] FM HDT kg · No. mol % wt % (%) (%) kg/cm² ° C. cm/cmEx. 32 0.8 94.0 93.7 0.26 16,600 115 6.7 Ex. 33 1.0 94.0 98.2 0.2915,700 112 6.5

EXAMPLE 34 Preparation of Propylene Block Copolymer

[0763] [Prepolymerization]

[0764] Prepolymerization was carried out in the same manner as inExample 27 except that diphenyldimethoxysilane was used in place ofDTBMS, to obtain a prepolymerized catalyst [Ih].

[0765] [Polymerization]

[0766] Polymerization was carried out in the same manner as in Example27 except that the prepolymerized catalyst [Ih] was used in place of theprepolymerized catalyst [Ic], and the polymerization time was changed to35 minutes.

[0767] The results are shown in Table 9. TABLE 9 23° C. n-Decane- Bulksoluble component specific Ethylene Activity MFR gravity Content content[η] No. g/mol-Ti g/10 min g/ml wt % mol % dl/g Ex. 34 45,300 49 0.47 9.040.2 6.0 23° C. n-Decane-insoluble component Boiling heptane- Ethyleneinsoluble component IZ content Content [M₅] [M₃] FM HDT kg · No. mol %wt % (%) (%) kg/cm² ° C. cm/cm Ex. 34 1.0 94.2 99.0 0.30 17,000 114 7.0

EXAMPLE 35 Preparation of Propylene Block Copolymer

[0768] [Polymerization]

[0769] Into a 17-liter autoclave were introduced 3 kg of propylene and50 liters of hydrogen, and the temperature of the system was raised to60° C. Then, 15 mmol of triethylaluminum, 15 mmol of DTBMS and 0.03 mmol(in terms of titanium atom) of the prepolymerized catalyst [I-4]obtained in Example 16 were added to the autoclave. The temperature ofthe system was raised to 70° C., and the same temperature was kept for40 minutes to perform homopolymerization of propylene.

[0770] After the end of the homopolymerization of propylene, the ventvalve was opened to release the autoclave until the pressure reachedatmospheric pressure.

[0771] After the release of pressure, copolymerization of ethylene andpropylene was carried out in the following manner. Ethylene andpropylene were fed to the polymerization reactor at rates of 240 Nl/hrand 960 Nl/hr, respectively. The vent of the polymerizer was adjusted onits opening degree so that the pressure in the reactor became 10kg/cm²-G. The polymerization was carried out for 80 minutes with keepingthe temperature at 70° C. To the reaction system was added a smallamount of ethanol to terminate the polymerization reaction, and theunreacted gas was purged out from the reactor. The resulting whitepowder was dried at 80° C. under reduced pressure.

[0772] The results are shown in Table 10.

EXAMPLE 36 Preparation of Propylene Block Copolymer

[0773] [Preparation of Solid Titanium Catalyst Component (A-2k)]

[0774] The procedure of the preparation of the solid titanium catalystcomponent (A-2) was repeated except that 4.48 ml of2-isopropyl-2-isobutyl-1,3-dimethoxypropane was used in place of IPAMP,to obtain a solid titanium catalyst component (A-2k).

[0775] The solid titanium catalyst component (A-2k) thus obtained had acomposition comprising 2.1% by weight of titanium, 63% by weight ofchlorine, 20% by weight of magnesium and 7.9% by weight of2-isopropyl-2-isobutyl-1,3-dimethoxypropane.

[0776] [Preparation of Prepolymerized Catalyst [Il]]

[0777] A 400 ml four-necked glass reactor equipped with a stirrer wascharged with 100 ml of purified hexane, 3 mmol of triethylaluminum and1.0 mmol (in terms of titanium atom) of the solid titanium catalystcomponent (A-2k) obtained as above in a nitrogen atmosphere. Then,propylene was fed to the reactor at a rate of 3.5 1/hr for 1 hour. Thepolymerization temperature was kept at 20° C.

[0778] After the end of propylene feeding, the reactor was purged withnitrogen, and washing operation consisting of removal of a supernatantand addition of purified hexane was carried out twice, to obtain aprepolymerized catalyst [Il], which was resuspended in purified hexane,and the whole suspension was stored in a catalyst bottle.

[0779] [Polymerization]

[0780] Polymerization was carried in the same manner as in Example 35except that the prepolymerized catalyst [Il] was used in place of theprepolymerized catalyst [Ij], and2-isopropyl-2-isobutyl-1,3-dimethoxypropane was used in place of DTBMS.

[0781] The results are shown in Table 10. TABLE 10 23° C. n-Decane- Bulksoluble component specific Ethylene Activity MFR gravity Content content[η] No. g/mol-Ti g/10 min g/ml wt % mol % dl/g Ex. 35 75,000 43 0.46 8.737.2 6.7 Ex. 36 73,900 48 0.45 9.0 39.2 6.4 23° C. n-Decane-insolublecomponent Boiling heptane- Ethylene insoluble component IZ contentContent [M₅] [M₃] FM HDT kg · No. mol % wt % (%) (%) kg/cm² ° C. cm/cmEx. 35 1.0 94.2 98.7 0.33 17,000 116 6.8 Ex. 36 1.1 94.0 98.3 0.3215,600 112 6.7

EXAMPLE 37 Preparation of Propylene Block Copolymer

[0782] [Polymerization]

[0783] Into a 17-liter autoclave were introduced 3 kg of propylene and45 liters of hydrogen, and the temperature of the system was raised to60° C. Then, 15 mmol of triethylaluminum, 15 mmol of2-isopentyl-2-isopropyl-1,3-dimethoxypropane (IPAMP) and 0.05 mmol (interms of titanium atom) of the prepolymerized catalyst [I] as obtainedin Example 1 were added to the autoclave. The temperature of the systemwas raised to 70° C., and the same temperature was kept for 40 minutesto perform homopolymerization of propylene.

[0784] After the end of the homopolymerization, the vent valve wasopened to release the autoclave until the pressure reached atmosphericpressure.

[0785] After the release of pressure, copolymerization of ethylene andpropylene was carried out in the following manner. Ethylene andpropylene were fed to the polymerization reactor at rates of 240 Nl/hrand 960 Nl/hr, respectively. The vent of the reactor was adjusted on itsopening degree so that the pressure in the polymerizer became 10kg/cm²-G. The polymerization was carried out for 50 minutes with keepingthe temperature at 70° C. To the reaction system was added a smallamount of ethanol to terminate the polymerization reaction, and theunreacted gas was purged out from the reactor.

[0786] The results are shown in Table 11.

EXAMPLE 38

[0787] [Polymerization]

[0788] Into a 17-liter autoclave were introduced 3 kg of propylene and45 liters of hydrogen, and the temperature of the system was raised to60° C. Then, 15 mmol of triethylaliuminum, 15 mmol ofdicyclopentyldimethoxysilane (DCPMS) and 0.05 mmOl (in terms of titaniumatom) of the prepolymerized catalyst [I-2] as obtained in Example 8 wereadded to the autoclave. The temperature of the system was raised to 70°C., and the same temperature was kept for 40 minutes to performhomopolymerization of propylene.

[0789] After the end of the homopolymerization, the vent valve wasopened to release the autoclave until the pressure reached atmosphericpressure.

[0790] After the release of pressure, copolymerization of ethylene andpropylene was carried out in the following manner. Ethylene andpropylene were fed to the polymeriation reactor at rates of 240 Ni/hrand 960 Nl/hr, respectively. The vent of the reactor was adjusted on itsopening degree so that the pressure in the polymerizer became 10kg/cm2-G. The polymerization was carried out for 50 minutes with keepingthe temperature at 70° C. To the reaction system was added a smallamount of ethanol to terminate the polymerization reaction, and theunreacted gas was purged out from the reactor.

[0791] The results are shown in Table 11.

EXAMPLE 39 Preparation of Homopolypropylene

[0792] [Polymerization]

[0793] Polymerization was carried out in the same manner as in Example 1except that the prepolymerized catalyst (1-2] as obtained in Example 8was used. The results are shown in Table 11.

EXAMPLE 40 Preparation of Homopolypropylene

[0794] [Polymerization]

[0795] Polymerization was carried out in the same manner as in Example 2except that the prepolymerized catalyst [I-2 ]as obtained in Example 8was used. The results are shown in Table 11.

EXAMPLE 41 Preparation of Homopolypropylene

[0796] [Polymerization]

[0797] Polymerization was carried out in the same manner as in Example 2except that the prepolymerized catalyst [I-2]as obtained in Example 8was used, and 8 liters of hydrogen were used in place of 20 liters. Theresults are shown in Table 11. TABLE 11 23° C. n-Decane-insolublecomponent 23° C. n-Decane-soluble component Boiling heptane- Bulkspecific Ethylene Ethylene insoluble component Activity MFR gravityContent content [η] content Content [M₅] [M₃] FM HDT IZ No. g/mol-Tig/10 min g/ml wt % mol % dl/g mol % wt % (%) (%) kg/cm² ° C. kg · cm/cmEx.37 35,400 46 0.45 9.6 38.6 2.5 0.7 94.2 98.8 0.30 14,900 112 3.5Ex.38 36,400 52 0.45 9.1 37.0 2.3 0.8 94.4 99.2 0.27 15,100 113 3.4Ex.39 31,100 112 0.46 1.0 — — — 96.9 99.4 0.27 — — — Ex.40 29,800 560.47 0.8 — — — 96.3 99.3 0.27 — — — Ex.41 29,900 29 0.47 0.8 — — — 96.899.3 0.25 — — —

What is claimed:
 1. An olefin polymerization catalyst (2) formed from:(I-2) a contact product obtained by contacting in the absence ofpolymerizable olefin monomer: (A) a solid titanium catalyst componentcomprising magnesium, titanium, halogen and an organic ester as electrondonor; (3) an organometallic compound catalyst component and (D) acompound having at least two ether linkages spaced by plural atoms;(II-2) (C) an organosilicon compound represented by the followingformula (c-i) R_(a) ₂Si(OR^(b))₂  (c-i) R^(a) is a secondary or tertiaryhydrocarbon group, and both R^(a) may be the same or different, R^(b) isa hydrocarbon group of 1 to 4 carbon atoms and both OR^(b) may be thesame or different; and, optionally, (III) an organometallic compoundcatalyst component.
 2. The olefin polymerization catalyst as claimed inclaim 1 , wherein the organosilicon compound (C) is represented by thefollowing formula (c-ii):

wherein R^(a) and R^(c) are each independently a cyclopentenyl group, asubstituted cyclopentenyl group, a cyclopentenyl group, a substitutedcyclopentenyl group, a cyclopentadienyl group, a substitutedcyclopentadienyl group or a hydrocarbon group whose carbon adjacent toSi is secondary or tertiary carbon.
 3. The olefin polymerizationcatalyst as claimed in claim 1 , wherein the compound (D) having atleast two ether linkages present through plural atoms is represented bythe following formula:

wherein n is an integer satisfying the condition 2≦n≦10, R¹ to R²⁶ areeach a substituent having at least one atom selected from the groupconsisting of carbon, hydrogen, oxygen, halogen, nitrogen, sulfur,phosphorous, boron and silicon, any optional combination of R¹ to R²⁶may form together a ring other than a benzene ring, and the main chainof the compound may contain atoms other than carbon.
 4. An olefinpolymerization catalyst (2 a) formed from: (Ia-2) a prepolymerizedcatalyst component obtained by prepolymerizing an olefin of 2 or morecarbon atoms in the presence of (A) a solid titanium catalyst componentcomprising magnesium, titanium, halogen and a polycarboxylic esterselected from the group consisting of compounds of the formulas

wherein R¹ is a hydrocarbon group which may have a substituent, R², R³,R⁴, R⁵ and R⁶ are hydrogen or hydrocarbon group which may besubstituted, wherein any substituent group contains N, O or S atom, andR³ and R⁴ may be linked to each other to form a cyclic structure; (B)anorganometallic compound catalyst component, and (D) a compound having atleast two ether linkages spaced by plural atoms; (II-2) (C) anorganosilicon compound represented by the following formula (c-i) R^(a)₂Si(OR^(b))₂  (c-i) wherein R^(a) is a secondary or tertiary hydrocarbongroup, and both R^(a) may be the same or different, R^(b) is ahydrocarbon group of 1 to 4 carbon atoms, and both OR^(b) may be thesame or different; and, optionally (III) an organometallic compoundcatalyst component.
 5. The olefin polymerization catalyst as claimed inclaim 4 , wherein the organosilicon compound (C) is represented by thefollowing formula

wherein R^(a) and R^(c) are each independently a cyclopentyl group, asubstituted cyclopentyl group, a cyclopentenyl group, a substitutedcyclopentenyl group, a cyclopentadienyl group, a substitutedcyclopentadienyl group or a hydrocarbon group whose carbon adjacent toSi is secondary or tertiary carbon.
 6. The olefin polymerizationcatalyst as claimed in claim 4 , wherein the compound (D) having atleast two ether linkages present through plural atoms is represented bythe following formula:

wherein n is an integer satisfying the condition 2≦n≦10, R¹ to R²⁶ areeach a substituent having at least one atom selected from the groupconsisting of carbon, hydrogen, oxygen, halogen, nitrogen, sulfur,phosphorus, boron and silicon, any optional combination of R¹ to R²⁶ mayform together a ring other than a benzene ring, and the main chain ofthe compound may contain atoms other than carbon.